qemu: Add QEMU version computation to QMP probing

With QMP capability probing, the version was not set.
virsh version returns:
...
Cannot extract running QEMU hypervisor version

This is fixed by computing caps->version from QMP major,
minor, micro values.
Signed-off-by: NViktor Mihajlovski <mihajlov@linux.vnet.ibm.com>

src/qemu/qemu_capabilities.c

@@ -2377,6 +2377,7 @@ qemuCapsInitQMP(qemuCapsPtr caps,
         goto cleanup;
     }
 
+    caps->version = major * 1000000 + minor * 1000 + micro;
     caps->usedQMP = true;
 
     qemuCapsInitQMPBasic(caps);