perf scripts python: exported-sql-viewer.py: Fix time chart call tree

Using Python version 3.8.2 and PySide2 version 5.14.0, time chart call tree
would not expand the tree to the result. Fix by using setExpanded().

Example:

  $ perf record -e intel_pt//u uname
  Linux
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.034 MB perf.data ]
  $ perf script --itrace=bep -s ~/libexec/perf-core/scripts/python/export-to-sqlite.py perf.data.db branches calls
  2020-06-26 15:32:14.928997 Creating database ...
  2020-06-26 15:32:14.933971 Writing records...
  2020-06-26 15:32:15.535251 Adding indexes
  2020-06-26 15:32:15.542993 Dropping unused tables
  2020-06-26 15:32:15.549716 Done
  $ python3 ~/libexec/perf-core/scripts/python/exported-sql-viewer.py perf.data.db

  Select: Charts -> Time chart by CPU
  Move mouse over middle of chart
  Right-click and select Show Call Tree

Before: displays Call Tree but not expanded to selected time
After: displays Call Tree expanded to selected time

Fixes: e69d5df ("perf scripts python: exported-sql-viewer.py: Add ability for Call tree to open at a specified task and time")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200629091955.17090-7-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/scripts/python/exported-sql-viewer.py

@@ -1130,6 +1130,7 @@ def DisplayThreadAtTime(self, comm_id, thread_id, time):
 				child = self.model.index(row, 0, parent)
 				if child.internalPointer().dbid == dbid:
 					found = True
+					self.view.setExpanded(parent, True)
 					self.view.setCurrentIndex(child)
 					parent = child
 					break
@@ -1142,6 +1143,7 @@ def DisplayThreadAtTime(self, comm_id, thread_id, time):
 				return
 			last_child = None
 			for row in xrange(n):
+				self.view.setExpanded(parent, True)
 				child = self.model.index(row, 0, parent)
 				child_call_time = child.internalPointer().call_time
 				if child_call_time < time:
@@ -1154,9 +1156,11 @@ def DisplayThreadAtTime(self, comm_id, thread_id, time):
 			if not last_child:
 				if not found:
 					child = self.model.index(0, 0, parent)
+					self.view.setExpanded(parent, True)
 					self.view.setCurrentIndex(child)
 				return
 			found = True
+			self.view.setExpanded(parent, True)
 			self.view.setCurrentIndex(last_child)
 			parent = last_child