Update KillFilter to handle 'deleted' exe's.

Updates KillFilter so that it handles the case where the executable
linked to by /proc/PID/exe is updated or deleted.

Fixes LP Bug #967931.

Change-Id: I368a01383bf62b64b7579d573b8b84640dec03ae

nova/rootwrap/filters.py

@@ -117,6 +117,9 @@ class KillFilter(CommandFilter):
                 return False
         try:
             command = os.readlink("/proc/%d/exe" % int(args[1]))
+            # NOTE(dprince): /proc/PID/exe may have ' (deleted)' on
+            # the end if an executable is updated or deleted
+            command = command.rstrip(" (deleted)")
             if command not in self.args[1]:
                 # Affected executable not in accepted list
                 return False