e2e: remove unused ShortName from external driver definition

The name was meant to be used as shorter replacement for potentially
long CSI driver names, but was never used in practice.

test/e2e/storage/external/external.go

@@ -144,9 +144,6 @@ type driverDefinition struct {
 	// the default file system are enabled.
 	DriverInfo testsuites.DriverInfo
 
-	// ShortName is used to create unique names for test cases and test resources.
-	ShortName string
-
 	// StorageClass must be set to enable dynamic provisioning tests.
 	// The default is to not run those tests.
 	StorageClass struct {

test/e2e/storage/external/external_test.go

@@ -33,7 +33,6 @@ func TestDriverParameter(t *testing.T) {
 				"", // Default fsType
 			),
 		},
-		ShortName: "foo",
 		ClaimSize: "5Gi",
 	}
 	testcases := []struct {