UPSTREAM: video: fbdev: aty: do not leak uninitialized padding in clk…

… to userspace

'clk' is copied to a userland with padding byte(s) after 'vclk_post_div'
field unitialized, leaking data from the stack. Fix this ensuring all of
'clk' is initialized to zero.

BUG=chromium:762904
TEST=Build and run

Change-Id: I414c8ad7057bfb560bfd15d5342e45e4ea0edb52
References: torvalds/linux#441
Reported-by: sohu0106 <sohu0106@126.com>
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Guenter Roeck <groeck@chromium.org>
(cherry picked from commit 8e75f7a)
Reviewed-on: https://chromium-review.googlesource.com/673347
Reviewed-by: Dmitry Torokhov <dtor@chromium.org>

drivers/video/fbdev/aty/atyfb_base.c

@@ -1861,7 +1861,7 @@ static int atyfb_ioctl(struct fb_info *info, u_int cmd, u_long arg)
 #if defined(DEBUG) && defined(CONFIG_FB_ATY_CT)
 	case ATYIO_CLKR:
 		if (M64_HAS(INTEGRATED)) {
-			struct atyclk clk;
+			struct atyclk clk = { 0 };
 			union aty_pll *pll = &par->pll;
 			u32 dsp_config = pll->ct.dsp_config;
 			u32 dsp_on_off = pll->ct.dsp_on_off;