virtManager: Remove some unnecessary generatename collidelist usage

The libvirt callbacks will handle this for us already

virtManager/create.py

@@ -1497,8 +1497,7 @@ class vmmCreate(vmmGObjectUI):
         return virtinst.generatename.generate_name(basename,
             self.conn.get_backend().lookupByName,
             start_num=force_num and 1 or 2, force_num=force_num,
-            sep=not force_num and "-" or "",
-            collidelist=[vm.get_name() for vm in self.conn.list_vms()])
+            sep=not force_num and "-" or "")
 
 
     def _validate_install_page(self):

virtManager/snapshots.py

@@ -117,12 +117,10 @@ class vmmSnapshotNew(vmmGObjectUI):
         self.widget("snapshot-new-description").set_buffer(buf)
 
     def _reset_state(self):
-        collidelist = [s.get_xmlobj().name for s in self.vm.list_snapshots()]
         basename = "snapshot"
         cb = self.vm.get_backend().snapshotLookupByName
         default_name = generatename.generate_name(
-                basename, cb, sep="", start_num=1, force_num=True,
-                collidelist=collidelist)
+                basename, cb, sep="", start_num=1, force_num=True)
 
         self.widget("snapshot-new-name").set_text(default_name)
         self.widget("snapshot-new-name").emit("changed")