TEST-19-CGROUP: Skip on opensuse

OpenSUSE images seem to be unhappy with either how they are built
or what they are being asked to do.

The listed device-mapper failure is just one of the strange errors,
I have also seen it fail to propagate cgroup properties into new cgroups
that were previously guaranteed to exist.

test/units/testsuite-19.sh

@@ -3,6 +3,14 @@
 set -eux
 set -o pipefail
 
+. /etc/os-release
+# FIXME: This test fails on opensuse with the following error and others:
+# Apr 25 10:24:04 H (cat)[910]: device-mapper: create ioctl on ... failed: Device or resource busy
+if [[ "$ID" =~ "opensuse" ]]; then
+    echo "Skipping due to known unexpected behaviour in OpenSUSE kernels" >>/skipped
+    exit 77
+fi
+
 # shellcheck source=test/units/test-control.sh
 . "$(dirname "$0")"/test-control.sh