[PATCH] ext4: use kmemdup_nul() instead of kstrndup()

[Xianting Tian]

kmemdup_nul() is more efficient than kmemdup_nul() if
the size is known exactly.

The description of kstrndup() already suggested:
Note: Use kmemdup_nul() instead if the size is known exactly.

Signed-off-by: Xianting Tian <xianting_tian@xxxxxxx>
---
 fs/ext4/super.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 330957e..be37556 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4016,7 +4016,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	}
 
 	if (sbi->s_es->s_mount_opts[0]) {
-		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
+		char *s_mount_opts = kmemdup_nul(sbi->s_es->s_mount_opts,
 					      sizeof(sbi->s_es->s_mount_opts),
 					      GFP_KERNEL);
 		if (!s_mount_opts)
-- 
1.8.3.1