Drop the vm_running global variable

Use runstate_is_running() instead, which is introduced by this commit.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
diff --git a/monitor.c b/monitor.c
index 68956a5..442b4cf 100644
--- a/monitor.c
+++ b/monitor.c
@@ -2632,7 +2632,7 @@
 static void do_info_status(Monitor *mon, QObject **ret_data)
 {
     *ret_data = qobject_from_jsonf("{ 'running': %i, 'singlestep': %i }",
-                                    vm_running, singlestep);
+                                    runstate_is_running(), singlestep);
 }
 
 static qemu_acl *find_acl(Monitor *mon, const char *name)
@@ -2825,7 +2825,7 @@
 
 static void do_loadvm(Monitor *mon, const QDict *qdict)
 {
-    int saved_vm_running  = vm_running;
+    int saved_vm_running  = runstate_is_running();
     const char *name = qdict_get_str(qdict, "name");
 
     vm_stop(RSTATE_RESTORE);