btrfs: No need to check !(flags & MS_RDONLY) twice

Code cleanup.
The code block is for !(*flags & MS_RDONLY). We don't need
to check it again.
Signed-off-by: NGoldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: NOmar Sandoval <osandov@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/super.c

@@ -1788,8 +1788,7 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
 		}
 
 		if (fs_info->fs_devices->missing_devices >
-		     fs_info->num_tolerated_disk_barrier_failures &&
-		    !(*flags & MS_RDONLY)) {
+		     fs_info->num_tolerated_disk_barrier_failures) {
 			btrfs_warn(fs_info,
 				"too many missing devices, writeable remount is not allowed");
 			ret = -EACCES;