wm: Add trailing null char after strncpy() in profiler.
wm: Add trailing null char after strncpy() in profiler.

Change-Id: I21b75176da92f605eab86a6bcbdc9fc13424988d

BUG=chromium-os:7030
TEST=built it

Review URL: http://codereview.chromium.org/3471013

joshfire/chromiumos-platform-window_manager,joshfire/chromiumos-platform-window_manager,joshfire/chromiumos-platform-window_manager,joshfire/chromiumos-platform-window_manager