Correct try bucket name for internal V8 bots on swarming

TBR=machenbach@chromium.org

No-Try: true
Bug: chromium:616879
Change-Id: I49d3f12216cdc2d26761e8f82fef18512d8eb6fd
Reviewed-on: https://chromium-review.googlesource.com/915141
Commit-Queue: Sergiy Byelozyorov <sergiyb@chromium.org>
Reviewed-by: Sergiy Byelozyorov <sergiyb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51257}

tools/try_perf.py

@@ -110,7 +110,7 @@ def main():
 
   swarming_bots = [bot for bot in options.bots if bot in SWARMING_BOTS]
   if swarming_bots:
-    _trigger_bots('luci.v8-internal', swarming_bots, options)
+    _trigger_bots('luci.v8-internal.try', swarming_bots, options)
 
 
 if __name__ == '__main__':  # pragma: no cover