bitbake: toasterui: fixing event.data clash

This patch fixes a name collision on the event.data
in the MetadataEvent class. event.data is used in the
event system as a copy of "d" in certain situations,
and this collision triggered a bug leading to data loss.

[YOCTO #6332]

(Bitbake rev: 3f191b7cfe95aea4d4e96babf001d62d45dd3aaa)

Signed-off-by: Alexandru DAMIAN <alexandru.damian@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/event.py

@@ -594,7 +594,7 @@ class MetadataEvent(Event):
     def __init__(self, eventtype, eventdata):
         Event.__init__(self)
         self.type = eventtype
-        self.data = eventdata
+        self._localdata = eventdata
 
 class SanityCheck(Event):
     """