Fix up the logic and remove our extra try's around UUID lookups

NodeInstance.py

@@ -104,13 +104,13 @@ class NodeInstance(threading.Thread):
 
             # Remove any non-running VMs from our list
             for domain in self.domain_list:
-                try:
                 dom = pvcdomf.lookupByUUID(conn, domain)
+                if dom == None:
+                    self.domain_list.remove(domain)
+                else:
                     state = dom.state()[0]
                     if state != libvirt.VIR_DOMAIN_RUNNING:
                         self.domain_list.remove(domain)
-                except:
-                    self.domain_list.remove(domain)
 
             # Set our information in zookeeper
             self.memfree = conn.getFreeMemory()

VMInstance.py

@@ -26,11 +26,8 @@ class VMInstance:
             print('>>> %s - Failed to open local libvirt connection.' % self.domuuid)
             exit(1)
     
-        try:
         self.dom = pvcdomf.lookupByUUID(conn, self.domuuid)
         conn.close()
-        except libvirt.libvirtError:
-            self.dom = None
 
         # Watch for changes to the hypervisor field in Zookeeper
         @zk.DataWatch(self.zkey + '/hypervisor')
@@ -151,9 +148,8 @@ class VMInstance:
         print('>>> %s - Receiving migration' % self.domuuid)
         self.inreceive = True
         while True:
-            try:
             self.dom = pvcdomf.lookupByUUID(conn, self.domuuid)
-            except:
+            if self.dom == None:
                 time.sleep(0.2)
                 continue