generic/413, xfs/260: Improve format operation for PMD fault testing

1) Simple code and fix the wrong value of stripe_width by _scratch_mkfs_geom().
2) Get hugepage size by _get_hugepagesize() and replace fixed 2M with
   hugepage size because hugepage size/PMD_SIZE is not 2M on some
   arches(e.g. hugepage size/PMD_SIZE is 512M on arm64).
3) For debugging, redirect the output of mkfs to $seqres.full.

Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>

common/rc

@@ -170,6 +170,16 @@ _get_filesize()
     stat -c %s "$1"
 }
 
+# Get hugepagesize in bytes
+_get_hugepagesize()
+{
+	local hugepgsz=$(awk '/Hugepagesize/ {print $2}' /proc/meminfo)
+	# Call _notrun if $hugepgsz is not a number
+	echo "$hugepgsz" | egrep -q ^[0-9]+$ || \
+		_notrun "Cannot get the value of Hugepagesize"
+	echo $((hugepgsz * 1024))
+}
+
 _mount()
 {
     $MOUNT_PROG `_mount_ops_filter $*`