fs/ext4/super.c: use strreplace() in ext4_fill_super()

This makes a very large function a little smaller.
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/ext4/super.c

@@ -3420,7 +3420,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	unsigned long journal_devnum = 0;
 	unsigned long def_mount_opts;
 	struct inode *root;
-	char *cp;
 	const char *descr;
 	int ret = -ENOMEM;
 	int blocksize, clustersize;
@@ -3456,8 +3455,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 #endif
 
 	/* Cleanup superblock name */
-	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
-		*cp = '!';
+	strreplace(sb->s_id, '/', '!');
 
 	/* -EINVAL is default */
 	ret = -EINVAL;