Fix uninitialized variables

detecet by

	http://honk.sigxcpu.org:8001/job/libvirt-build/348/console
(cherry picked from commit d01e427e)

src/qemu/qemu_monitor.c

@@ -2373,7 +2373,7 @@ int qemuMonitorRemoveHostNetwork(qemuMonitorPtr mon,
                                  int vlan,
                                  const char *netname)
 {
-    int ret;
+    int ret = -1;
     VIR_DEBUG("mon=%p netname=%s",
           mon, netname);
 
@@ -2505,7 +2505,7 @@ int qemuMonitorAttachDrive(qemuMonitorPtr mon,
           mon, drivestr,
           controllerAddr->domain, controllerAddr->bus,
           controllerAddr->slot, controllerAddr->function);
-    int ret;
+    int ret = 1;
 
     if (!mon) {
         virReportError(VIR_ERR_INVALID_ARG, "%s",