crash-reporter: Clean up angle brackets in template types.

C++11 no longer has the angle bracket pitfall in template types.

BUG=None
TEST=`FEATURES=test emerge-$BOARD crash-reporter`

Change-Id: I25410c458f730d8e0a38237b3711439262a1b774
Reviewed-on: https://chromium-review.googlesource.com/219194


Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Ben Chan <benchan@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>