check: support include/exclude of sub groups

Allow including and/or excluding tests by test dir and group.
-g and -x command line arguments can take the form of
<subdir>/<group>.

For example:

./check -n -g xfs/quick
./check -n -g stress -x xfs/stress
./check -n -g xfs/punch -x dangerous_fuzzers

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>

check

@@ -105,6 +105,14 @@ get_group_list()
 {
 	local grp=$1
 	local grpl=""
+	local sub=$(dirname $grp)
+
+	if [ -n "$sub" -a "$sub" != "." -a -d "$SRC_DIR/$sub" ]; then
+		# group is given as <subdir>/<group> (e.g. xfs/quick)
+		grp=$(basename $grp)
+		get_sub_group_list $sub $grp
+		return
+	fi
 
 	for d in $SRC_GROUPS $FSTYP; do
 		if ! test -d "$SRC_DIR/$d" ; then