[PATCH v3 2/2] staging: rtl8723bs: use guard clause for stainfo check

[Lin YuChen <starpt.official@gmail.com>]

Continue the refactor of rtw_aes_decrypt() by introducing a guard
clause for the stainfo check. This allows the subsequent multicast
and unicast decryption logic to be moved one indentation level to
the left, further improving code readability.

Signed-off-by: Lin YuChen <starpt.official@gmail.com>
---
v3: Use "return _FAIL" instead of "res = _FAIL; goto exit" for the stainfo
    guard clause.
v3: Revert unrelated formatting and line-breaking changes (e.g., in
    netdev_dbg calls) to keep the diff focused only on indentation
    changes, as suggested by Dan Carpenter.
v2: Split the refactoring into a separate patch to make it easier to
    verify logic changes.

 drivers/staging/rtl8723bs/core/rtw_security.c | 96 +++++++++----------
 1 file changed, 47 insertions(+), 49 deletions(-)

diff --git a/drivers/staging/rtl8723bs/core/rtw_security.c b/drivers/staging/rtl8723bs/core/rtw_security.c
index 3c89e911ac2d..cf910c268bb3 100644
--- a/drivers/staging/rtl8723bs/core/rtw_security.c
+++ b/drivers/staging/rtl8723bs/core/rtw_security.c
@@ -1216,66 +1216,64 @@ u32 rtw_aes_decrypt(struct adapter *padapter, u8 *precvframe)
 	if (prxattrib->encrypt != _AES_)
 		return _SUCCESS;
 	stainfo = rtw_get_stainfo(&padapter->stapriv, &prxattrib->ta[0]);
-	if (stainfo) {
-		if (is_multicast_ether_addr(prxattrib->ra)) {
-			static unsigned long start;
-			static u32 no_gkey_bc_cnt;
-			static u32 no_gkey_mc_cnt;
-
-			if (!psecuritypriv->binstallGrpkey) {
-				res = _FAIL;
+	if (stainfo)
+		return _FAIL;
+	if (is_multicast_ether_addr(prxattrib->ra)) {
+		static unsigned long start;
+		static u32 no_gkey_bc_cnt;
+		static u32 no_gkey_mc_cnt;
 
-				if (start == 0)
-					start = jiffies;
+		if (!psecuritypriv->binstallGrpkey) {
+			res = _FAIL;
 
-				if (is_broadcast_mac_addr(prxattrib->ra))
-					no_gkey_bc_cnt++;
-				else
-					no_gkey_mc_cnt++;
-
-				if (jiffies_to_msecs(jiffies - start) > 1000) {
-					if (no_gkey_bc_cnt || no_gkey_mc_cnt) {
-						netdev_dbg(padapter->pnetdev,
-							   FUNC_ADPT_FMT " no_gkey_bc_cnt:%u, no_gkey_mc_cnt:%u\n",
-							   FUNC_ADPT_ARG(padapter),
-							   no_gkey_bc_cnt,
-							   no_gkey_mc_cnt);
-					}
-					start = jiffies;
-					no_gkey_bc_cnt = 0;
-					no_gkey_mc_cnt = 0;
-				}
+			if (start == 0)
+				start = jiffies;
 
-				goto exit;
-			}
+			if (is_broadcast_mac_addr(prxattrib->ra))
+				no_gkey_bc_cnt++;
+			else
+				no_gkey_mc_cnt++;
 
-			if (no_gkey_bc_cnt || no_gkey_mc_cnt) {
-				netdev_dbg(padapter->pnetdev,
-					   FUNC_ADPT_FMT " gkey installed. no_gkey_bc_cnt:%u, no_gkey_mc_cnt:%u\n",
-					   FUNC_ADPT_ARG(padapter),
-					   no_gkey_bc_cnt,
-					   no_gkey_mc_cnt);
+			if (jiffies_to_msecs(jiffies - start) > 1000) {
+				if (no_gkey_bc_cnt || no_gkey_mc_cnt) {
+					netdev_dbg(padapter->pnetdev,
+						   FUNC_ADPT_FMT " no_gkey_bc_cnt:%u, no_gkey_mc_cnt:%u\n",
+						   FUNC_ADPT_ARG(padapter),
+						   no_gkey_bc_cnt,
+						   no_gkey_mc_cnt);
+				}
+				start = jiffies;
+				no_gkey_bc_cnt = 0;
+				no_gkey_mc_cnt = 0;
 			}
-			start = 0;
-			no_gkey_bc_cnt = 0;
-			no_gkey_mc_cnt = 0;
 
-			prwskey = psecuritypriv->dot118021XGrpKey[prxattrib->key_index].skey;
-			if (psecuritypriv->dot118021XGrpKeyid != prxattrib->key_index) {
-				res = _FAIL;
-				goto exit;
-			}
-		} else {
-			prwskey = &stainfo->dot118021x_UncstKey.skey[0];
+			goto exit;
 		}
 
-		length = ((union recv_frame *)precvframe)->u.hdr.len - prxattrib->hdrlen - prxattrib->iv_len;
-
-		res = aes_decipher(prwskey, prxattrib->hdrlen, pframe, length);
+		if (no_gkey_bc_cnt || no_gkey_mc_cnt) {
+			netdev_dbg(padapter->pnetdev,
+				   FUNC_ADPT_FMT " gkey installed. no_gkey_bc_cnt:%u, no_gkey_mc_cnt:%u\n",
+				   FUNC_ADPT_ARG(padapter),
+				   no_gkey_bc_cnt,
+				   no_gkey_mc_cnt);
+		}
+		start = 0;
+		no_gkey_bc_cnt = 0;
+		no_gkey_mc_cnt = 0;
 
+		prwskey = psecuritypriv->dot118021XGrpKey[prxattrib->key_index].skey;
+		if (psecuritypriv->dot118021XGrpKeyid != prxattrib->key_index) {
+			res = _FAIL;
+			goto exit;
+		}
 	} else {
-		res = _FAIL;
+		prwskey = &stainfo->dot118021x_UncstKey.skey[0];
 	}
+
+	length = ((union recv_frame *)precvframe)->u.hdr.len - prxattrib->hdrlen - prxattrib->iv_len;
+
+	res = aes_decipher(prwskey, prxattrib->hdrlen, pframe, length);
+
 exit:
 	return res;
 }
-- 
2.34.1