Rename the "rv" variants to avoid clashes

The current variant name RHEL.7.devel.x86_64 clashes with existing
filters enabling this test on all architectures and actually corrupting
the cartesian product. Let's use `-` to separate the parts.
Signed-off-by: NLukáš Doktor <ldoktor@redhat.com>

qemu/tests/cfg/spice.cfg

@@ -13,11 +13,11 @@
     virtio_port_name_prefix_virt-tests-vm1 = "com.redhat.spice."
   
     variants:
-        -RHEL.6.devel.x86_64:
+        - RHEL-6-devel-x86_64:
             image_name_vm2 = images/rhel6devel-64_client
-        -RHEL.6.devel.i386:
+        - RHEL-6-devel-i386:
             image_name_vm2 = images/rhel6devel-32_client
-        -RHEL.7.devel.x86_64:
+        - RHEL-7-devel-x86_64:
             image_name_vm2 = images/rhel7devel-64_client
     variants:
         - fullscreen_setup: