common/rc: avoid mkfs option conflicts in _scratch_mkfs_xfs_supported

In recent mkfs.xfs updates in xfsprogs, commit 9090e187bc3e ("mkfs:
add respecification detection to generic parsing") added
re-specification detection to "-m" option, it causes several tests
_notrun if MKFS_OPTIONS has the same options as those being tested
in _scratch_mkfs_xfs_supported(), because they're specified multiple
times.

	MKFS_OPTIONS="-m crc=0" ./check xfs/001
	xfs/001 3s ... [not run] mkfs.xfs doesn't have crc feature

Fix it by creating XFS again without MKFS_OPTIONS in
_scratch_mkfs_xfs_supported(), in case there's conflict between
MKFS_OPTIONS and mkfs_opts, like what we do in _scratch_mkfs_xfs().

Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>

common/rc

@@ -473,11 +473,20 @@ _scratch_mkfs_xfs_opts()
 
 _scratch_mkfs_xfs_supported()
 {
-	mkfs_opts=$*
+	local mkfs_opts=$*
 
 	_scratch_options mkfs
 
 	$MKFS_XFS_PROG -N $MKFS_OPTIONS $SCRATCH_OPTIONS $mkfs_opts $SCRATCH_DEV
+	local mkfs_status=$?
+
+	# a mkfs failure may be caused by conflicts between $MKFS_OPTIONS and
+	# $mkfs_opts, try again without $MKFS_OPTIONS
+	if [ $mkfs_status -ne 0 -a -n "$mkfs_opts" ]; then
+		$MKFS_XFS_PROG -N $SCRATCH_OPTIONS $mkfs_opts $SCRATCH_DEV
+		mkfs_status=$?
+	fi
+	return $mkfs_status
 }
 
 _scratch_mkfs_xfs()