[PATCH 1/1] btrfs: scrub: Fix use of uninitialized variable

['Guanjun' <guanjun@linux.alibaba.com>]

From: Guanjun <guanjun@linux.alibaba.com>

'ret' will be uninitialized in case that the logical_length
is 0. Even if the caller has already ensured that logical_length
is greater than 0, we still need to fix this issue. Due to the
compiler may complain like this:

fs/btrfs/scrub.c: In function ‘scrub_simple_mirror.constprop’:
fs/btrfs/scrub.c:2123:9: error: ‘ret’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
 2123 |  return ret;
      |         ^~~

Fixes: 09022b14fafc (btrfs: scrub: introduce dedicated helper to scrub simple-mirror based range)
Signed-off-by: Guanjun <guanjun@linux.alibaba.com>
---
 fs/btrfs/scrub.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index a01807cbd4d4..13024131f77d 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -2071,7 +2071,7 @@ static int scrub_simple_mirror(struct scrub_ctx *sctx,
 	struct btrfs_fs_info *fs_info = sctx->fs_info;
 	const u64 logical_end = logical_start + logical_length;
 	u64 cur_logical = logical_start;
-	int ret;
+	int ret = 0;
 
 	/* The range must be inside the bg */
 	ASSERT(logical_start >= bg->start && logical_end <= bg->start + bg->length);
-- 
2.39.3