virtual_sdcard: Move shutdown debugging to "klippy:analyze_shutdown" event

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/extras/virtual_sdcard.py

@@ -16,8 +16,6 @@ DEFAULT_ERROR_GCODE = """
 class VirtualSD:
     def __init__(self, config):
         self.printer = config.get_printer()
-        self.printer.register_event_handler("klippy:shutdown",
-                                            self.handle_shutdown)
         # sdcard state
         sd = config.get('path')
         self.sdcard_dirname = os.path.normpath(os.path.expanduser(sd))
@@ -46,7 +44,9 @@ class VirtualSD:
         self.gcode.register_command(
             "SDCARD_PRINT_FILE", self.cmd_SDCARD_PRINT_FILE,
             desc=self.cmd_SDCARD_PRINT_FILE_help)
-    def handle_shutdown(self):
+        self.printer.register_event_handler("klippy:analyze_shutdown",
+                                            self._handle_analyze_shutdown)
+    def _handle_analyze_shutdown(self, msg, details):
         if self.work_timer is not None:
             self.must_pause_work = True
             try: