qemu: Remove non null 'vm' check from qemuMonitorOpen

The prototype requires not passing a NULL in the parameter and the callers
all would fail far before this code would fail if 'vm' was NULL, so just
remove the check.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

src/qemu/qemu_monitor.c

@@ -910,8 +910,7 @@ qemuMonitorOpen(virDomainObjPtr vm,
     case VIR_DOMAIN_CHR_TYPE_UNIX:
         hasSendFD = true;
         if ((fd = qemuMonitorOpenUnix(config->data.nix.path,
-                                      vm ? vm->pid : 0,
-                                      timeout)) < 0)
+                                      vm->pid, timeout)) < 0)
             return NULL;
         break;