CHROMIUM: Input: cyapa - return -ENOMEM if kasprintf fails in probe

CHROMIUM: Input: cyapa - return -ENOMEM if kasprintf fails in probe

"ret" is being returned unitialized in this error path.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
BUG=chromium-os:32389
TEST=builds without this warning:
  cyapa.c: In function 'cyapa_probe':
  cyapa.c:1779:6: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized]

Change-Id: I8ba5ecf03a99d13df808cf83b7a68a13d3891fab
Reviewed-on: https://gerrit.chromium.org/gerrit/26803
Reviewed-by: Benson Leung <bleung@chromium.org>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Tested-by: Daniel Kurtz <djkurtz@chromium.org>
Commit-Ready: Daniel Kurtz <djkurtz@chromium.org>