Don't immediately fail on EINTR.

This CL retries drmOpenRender when EINTR is seen.
It also fixes the error handling to catch other failure
paths from drmOpenRender.

Bug: 180391767
Test: Compile, test graphics.

Change-Id: Ie4c5f1d661dbee10b4bb09d5857e84714ee5feda
1 file changed