Apple: glFlush() is not needed with CGLFlushDrawable()

<rdar://problem/14496373>

Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
(cherry picked from commit fa5ed99d8e809fb86e486a40273a4a6971055398)

src/glx/apple/apple_glx.c

diff --git a/src/glx/apple/apple_glx.c b/src/glx/apple/apple_glx.c
index 56cff64..4e2aa33 100644
--- a/src/glx/apple/apple_glx.c
+++ b/src/glx/apple/apple_glx.c
@@ -132,8 +132,6 @@
 {
    struct apple_glx_context *ac = ptr;
 
-   /* This may not be needed with CGLFlushDrawable: */
-   glFlush();
    apple_cgl.flush_drawable(ac->context_obj);
 }