Add missing clientset to EBS storage e2e test

A recent refactoring of these tests to use common pod functions requires that the StorageClassTest's Client be set.
This updates the "Invalid AWS KMS key" test to set its Client similar to other tests in the file.

test/e2e/storage/volume_provisioning.go

@@ -825,6 +825,7 @@ var _ = utils.SIGDescribe("Dynamic Provisioning", func() {
 		ginkgo.It("should report an error and create no PV", func() {
 			e2eskipper.SkipUnlessProviderIs("aws")
 			test := testsuites.StorageClassTest{
+				Client:      c,
 				Name:        "AWS EBS with invalid KMS key",
 				Provisioner: "kubernetes.io/aws-ebs",
 				Timeouts:    f.Timeouts,