xfs: use xfs_readonly_buftarg in xfs_remount_rw

Use xfs_readonly_buftarg instead of open coding it.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Hans Holmberg <[email protected]>
Reviewed-by: John Garry <[email protected]>
Signed-off-by: Carlos Maiolino <[email protected]>

Author: Christoph Hellwig

fs/xfs/xfs_super.c

@@ -2020,14 +2020,13 @@ xfs_remount_rw(
 	int error;
 
 	if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp &&
-	    bdev_read_only(mp->m_logdev_targp->bt_bdev)) {
+	    xfs_readonly_buftarg(mp->m_logdev_targp)) {
 		xfs_warn(mp,
 			"ro->rw transition prohibited by read-only logdev");
 		return -EACCES;
 	}
 
-	if (mp->m_rtdev_targp &&
-	    bdev_read_only(mp->m_rtdev_targp->bt_bdev)) {
+	if (mp->m_rtdev_targp && xfs_readonly_buftarg(mp->m_rtdev_targp)) {
 		xfs_warn(mp,
 			"ro->rw transition prohibited by read-only rtdev");
 		return -EACCES;