wm: Make transparent cursor not show up as 1x1 black dot.
wm: Make transparent cursor not show up as 1x1 black dot.

Guess I typoed this initially?

Also free the pixmap used to create the cursor.

BUG=chromium-os:10967
TEST=built and ran it and checked that dot was gone; ran existing tests

Review URL: http://codereview.chromium.org/6280007

Change-Id: I280e9f3e626c871ed4dbfe7a0580fdef6cf00d2d

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