[PATCH 1/2] riscv/purgatory: return bool from verify_sha256_digest

[Thorsten Blum <thorsten.blum@linux.dev>]

Change the function's return type from int to bool and return the result
of memcmp() directly to simplify the code.  While at it, cast ->start to
'const u8 *' to better match the expected type.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
 arch/riscv/purgatory/purgatory.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/riscv/purgatory/purgatory.c b/arch/riscv/purgatory/purgatory.c
index bbd5cfa4d741..15c72dafa3d8 100644
--- a/arch/riscv/purgatory/purgatory.c
+++ b/arch/riscv/purgatory/purgatory.c
@@ -17,7 +17,7 @@ u8 purgatory_sha256_digest[SHA256_DIGEST_SIZE] __section(".kexec-purgatory");
 
 struct kexec_sha_region purgatory_sha_regions[KEXEC_SEGMENT_MAX] __section(".kexec-purgatory");
 
-static int verify_sha256_digest(void)
+static bool verify_sha256_digest(void)
 {
 	struct kexec_sha_region *ptr, *end;
 	struct sha256_ctx sctx;
@@ -26,11 +26,10 @@ static int verify_sha256_digest(void)
 	sha256_init(&sctx);
 	end = purgatory_sha_regions + ARRAY_SIZE(purgatory_sha_regions);
 	for (ptr = purgatory_sha_regions; ptr < end; ptr++)
-		sha256_update(&sctx, (uint8_t *)(ptr->start), ptr->len);
+		sha256_update(&sctx, (const u8 *)(ptr->start), ptr->len);
 	sha256_final(&sctx, digest);
-	if (memcmp(digest, purgatory_sha256_digest, sizeof(digest)) != 0)
-		return 1;
-	return 0;
+
+	return memcmp(digest, purgatory_sha256_digest, sizeof(digest));
 }
 
 /* workaround for a warning with -Wmissing-prototypes */