Remove the concept of a border from weston_output.

The only user for this was the wayland backend with the GL renderer.  It is
not needed in the Pixman renderer because you can easily create subimages.
All of the fancy output matrix calculations can be replaced by a single
glViewport call.  Also, it didn't work with outputs located anywhere but
(0, 0) and I'm pretty sure output transformed outputs would break it too.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
diff --git a/src/compositor-wayland.c b/src/compositor-wayland.c
index bbadfc3..50c3239 100644
--- a/src/compositor-wayland.c
+++ b/src/compositor-wayland.c
@@ -570,7 +570,7 @@
 static int
 wayland_output_init_gl_renderer(struct wayland_output *output)
 {
-	int32_t fx, fy, fwidth, fheight;
+	int32_t fwidth = 0, fheight = 0;
 
 	if (output->frame) {
 		fwidth = frame_width(output->frame);
@@ -592,14 +592,6 @@
 			output->gl.egl_window) < 0)
 		goto cleanup_window;
 
-	if (output->frame) {
-		frame_interior(output->frame, &fx, &fy, NULL, NULL);
-		output->base.border.left = fx;
-		output->base.border.top = fy;
-		output->base.border.right = fwidth - output->base.width - fx;
-		output->base.border.bottom = fheight - output->base.height - fy;
-	}
-
 	return 0;
 
 cleanup_window: