Fix Xmethod for shared_ptr::use_count()

This was reported in https://bugzilla.redhat.com/show_bug.cgi?id=1749578

	* python/libstdcxx/v6/xmethods.py (SharedPtrUseCountWorker.__call__):
	Fix syntax error.

From-SVN: r275644

libstdc++-v3/ChangeLog

 2019-09-11  Jonathan Wakely  <jwakely@redhat.com>
 
+	* python/libstdcxx/v6/xmethods.py (SharedPtrUseCountWorker.__call__):
+	Fix syntax error.
+
 	* testsuite/20_util/result_of/sfinae_friendly_1.cc: Add -Wno-volatile
 	for C++2a and up. Define HAS_52748_FIXED and fix incorrect tests.
 	* testsuite/tr1/3_function_objects/result_of.cc: Add -Wno-volatile

libstdc++-v3/python/libstdcxx/v6/xmethods.py

@@ -739,7 +739,7 @@ class SharedPtrUseCountWorker(gdb.xmethod.XMethodWorker):
         return gdb.lookup_type('long')
 
     def __call__(self, obj):
-        refcounts = ['_M_refcount']['_M_pi']
+        refcounts = obj['_M_refcount']['_M_pi']
         return refcounts['_M_use_count'] if refcounts else 0
 
 class SharedPtrUniqueWorker(SharedPtrUseCountWorker):