drm/ast: free correct pointer in astfb_create() error paths

In the err_free_vram and err_release_fbi error paths in astfb_create(), we
attempt to free afbdev->sysram. The only jumps to these error paths occur
before we assign afbdev->sysram = sysram. Free sysram instead.
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161114030359.27852-1-andrew.donnellan@au1.ibm.com

drivers/gpu/drm/ast/ast_fb.c

@@ -253,7 +253,7 @@ static int astfb_create(struct drm_fb_helper *helper,
 err_release_fbi:
 	drm_fb_helper_release_fbi(helper);
 err_free_vram:
-	vfree(afbdev->sysram);
+	vfree(sysram);
 	return ret;
 }