drm/omap: fix error handling in omap_framebuffer_create()

When an error happens in omap_framebuffer_create(),
omap_framebuffer_create() calls omap_framebuffer_destroy() if the fb
struct has been allocated. However, that crashes, as
omap_framebuffer_destroy(), which calls drm_framebuffer_cleanup(),
should only be called after drm_framebuffer_init()

Fix this by just calling kfree() for the allocated fb when an error
happens.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/omap_fb.c

@@ -380,7 +380,7 @@ struct drm_framebuffer *omap_framebuffer_create(struct drm_device *dev,
 struct drm_framebuffer *omap_framebuffer_init(struct drm_device *dev,
 		struct drm_mode_fb_cmd2 *mode_cmd, struct drm_gem_object **bos)
 {
-	struct omap_framebuffer *omap_fb;
+	struct omap_framebuffer *omap_fb = NULL;
 	struct drm_framebuffer *fb = NULL;
 	const struct format *format = NULL;
 	int ret, i, n = drm_format_num_planes(mode_cmd->pixel_format);
@@ -451,8 +451,7 @@ struct drm_framebuffer *omap_framebuffer_init(struct drm_device *dev,
 	return fb;
 
 fail:
-	if (fb)
-		omap_framebuffer_destroy(fb);
+	kfree(omap_fb);
 
 	return ERR_PTR(ret);
 }