egl: fixes for object refcounts

eglMakeCurrent() would only deref the previous surfaces if the old and
new contexts were the same.  eglTerminate() should not touch TLS.
eglReleaseThread() needs to unbind the current context.

Change-Id: I7f4c090a287ee1e29e4708ae10679fb9d7d8c8c5
Related-Bug: 2964479
1 file changed