test-tool: use CHECK_FOR_ISCSI() helper macro

This removes a large amount of boilerplate code.

Signed-off-by: David Disseldorp <ddiss@suse.de>

test-tool/test_compareandwrite_invalid_dataout_size.c

@@ -55,13 +55,7 @@ test_compareandwrite_invalid_dataout_size(void)
         CHECK_FOR_THIN_PROVISIONING;
         CHECK_FOR_LBPPB_GT_1;
         CHECK_FOR_SBC;
-        if (sd->iscsi_ctx == NULL) {
-                const char *err = "[SKIPPED] This test is "
-                        "only supported for iSCSI backends";
-                logging(LOG_NORMAL, "%s", err);
-                CU_PASS(err);
-                return;
-        }
+        CHECK_FOR_ISCSI(sd);
 
         /* override transport queue_pdu callback for PDU manipulation */
         iscsi_drv_orig = *sd->iscsi_ctx->drv;