s390x: fix make standalone

A recent patch broke make standalone. The function find_word is not
available when running make standalone, replace it with a simple grep.

Fixes: 743cacf7 ("s390x: don't run migration tests under PV")
Reported-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-Id: <20221220175508.57180-1-imbrenda@linux.ibm.com>
Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
diff --git a/scripts/s390x/func.bash b/scripts/s390x/func.bash
index 2a941bb..6c75e89 100644
--- a/scripts/s390x/func.bash
+++ b/scripts/s390x/func.bash
@@ -21,7 +21,7 @@
 	"$cmd" "$testname" "$groups" "$smp" "$kernel" "$opts" "$arch" "$check" "$accel" "$timeout"
 
 	# run PV test case
-	if [ "$ACCEL" = 'tcg' ] || find_word "migration" "$groups"; then
+	if [ "$ACCEL" = 'tcg' ] || grep -q "migration" <<< "$groups"; then
 		return
 	fi
 	kernel=${kernel%.elf}.pv.bin