drm/vmwgfx: Delete an unnecessary check before the function call "vfree"

The vfree() function performs also input parameter validation.
Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/8060f2e9-5070-3c10-d55c-dc058e4ca20d@users.sourceforge.net
Link: http://patchwork.freedesktop.org/patch/msgid/f1a0fd83-4320-f3db-e1bb-3b9832a4429f@users.sourceforge.net

drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c

@@ -3625,9 +3625,7 @@ static int vmw_resize_cmd_bounce(struct vmw_sw_context *sw_context,
 				   (sw_context->cmd_bounce_size >> 1));
 	}
 
-	if (sw_context->cmd_bounce != NULL)
 	vfree(sw_context->cmd_bounce);
-
 	sw_context->cmd_bounce = vmalloc(sw_context->cmd_bounce_size);
 
 	if (sw_context->cmd_bounce == NULL) {