EGLWindow: remove redundant EGL_NONE to finish attrib list.

Only one EGL_NONE is needed to signal the end of the list.

BUG=angleproject:892

Change-Id: I7de349bef9d674344ccd1b2c4801d8b42c801299
Reviewed-on: https://chromium-review.googlesource.com/271157
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Corentin Wallez <cwallez@chromium.org>

util/EGLWindow.cpp

@@ -169,7 +169,6 @@ bool EGLWindow::initializeGL(OSWindow *osWindow)
         surfaceAttributes.push_back(EGL_TRUE);
     }
 
-    surfaceAttributes.push_back(EGL_NONE);
     surfaceAttributes.push_back(EGL_NONE);
 
     mSurface = eglCreateWindowSurface(mDisplay, mConfig, osWindow->getNativeWindow(), &surfaceAttributes[0]);