drm/omap: fix memory leak when FB init fails

omap_framebuffer_create() fails to unref all the gem objects if creating
the FB fails, leading to a memory leak.

Fix the loop so that it goes through all the reffed gem objects.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/omap_fb.c

@@ -379,7 +379,7 @@ struct drm_framebuffer *omap_framebuffer_create(struct drm_device *dev,
 	return fb;
 
 error:
-	while (--i > 0)
+	while (--i >= 0)
 		drm_gem_object_unreference_unlocked(bos[i]);
 
 	return fb;