am cb7e8c5e: libc: update alarm() implementation to return 0 on error.

Merge commit 'cb7e8c5ef3f5f60a848e469ed40610c8946fe7ac' into gingerbread-plus-aosp

* commit 'cb7e8c5ef3f5f60a848e469ed40610c8946fe7ac':
  libc: update alarm() implementation to return 0 on error.