perf scripts python: call-graph-from-sql.py: Remove use of setObjectName()

The object name is never used, so don't bother setting it.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20181001062853.28285-9-adrian.hunter@intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/scripts/python/call-graph-from-sql.py

@@ -269,7 +269,6 @@ class MainWindow(QMainWindow):
 
 		self.glb = glb
 
-		self.setObjectName("MainWindow")
 		self.setWindowTitle("Call Graph: " + glb.dbname)
 		self.move(100, 100)
 		self.resize(800, 600)