Skip blkio-weight test when no kernel BFQ support

Namely the Ubuntu 21.04 Kernel does not support BFQ.  Regardless of the
distro. skip this test if the required cgroup node doesn't exist.

Signed-off-by: Chris Evich <cevich@redhat.com>

test/e2e/run_test.go

@@ -582,6 +582,9 @@ USER bin`, BB)
 			if _, err := os.Stat("/sys/fs/cgroup/io.stat"); os.IsNotExist(err) {
 				Skip("Kernel does not have io.stat")
 			}
+			if _, err := os.Stat("/sys/fs/cgroup/system.slice/io.bfq.weight"); os.IsNotExist(err) {
+				Skip("Kernel does not support BFQ IO scheduler")
+			}
 			session := podmanTest.Podman([]string{"run", "--rm", "--blkio-weight=15", ALPINE, "sh", "-c", "cat /sys/fs/cgroup/io.bfq.weight"})
 			session.WaitWithDefaultTimeout()
 			Expect(session.ExitCode()).To(Equal(0))