Fix a multithreading bug in libagl's EGL.

The bug caused libagl to return 0 from eglGetError if an EGL error value
(including EGL_SUCCESS) was set on a different thread but not yet on the
current thread.

Bug: 3403756
Change-Id: Ifd965091d116745c2e22c121151ade9e78eb14c6
1 file changed