Fix for recent commit, should only do glFinish() on Windows.

source/blender/src/ghostwinlay.c

@@ -478,6 +478,7 @@ void window_make_active(Window *win) {
 }
 
 void window_swap_buffers(Window *win) {
+#ifdef _WIN32
 	// adding a glFinish() here is to prevent Geforce in 'full scene antialias' mode
 	// from antialising the Blender window. Officially a swapbuffers does a glFinish
 	// itself, so this feels really like a hack... but it won't harm. (ton)
@@ -487,6 +488,7 @@ void window_swap_buffers(Window *win) {
 	// discouraged for good performance. (brecht)
 	//
 	glFinish();
+#endif
 
 	GHOST_SwapWindowBuffers(win->ghostwin);
 }