drm/omap: fix omap_framebuffer_unpin() error handling

omap_framebuffer_unpin() check the return value of omap_gem_put_paddr()
and return immediately if omap_gem_put_paddr() fails.

This patch removes the check for the return value, and also removes the
return value of omap_framebuffer_unpin(), because:

 * Nothing checks the return value of omap_framebuffer_unpin(), and even
   something did check it, there's nothing the caller can do to handle
   the error.

 * If a omap_gem_put_paddr() fails, the framebuffer's other planes will
   be left unreleased. So it's better to call omap_gem_put_paddr() for
   all the planes, even if one would fail.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

drivers/gpu/drm/omapdrm/omap_drv.h

@@ -177,7 +177,7 @@ struct drm_framebuffer *omap_framebuffer_init(struct drm_device *dev,
 		struct drm_mode_fb_cmd2 *mode_cmd, struct drm_gem_object **bos);
 struct drm_gem_object *omap_framebuffer_bo(struct drm_framebuffer *fb, int p);
 int omap_framebuffer_pin(struct drm_framebuffer *fb);
-int omap_framebuffer_unpin(struct drm_framebuffer *fb);
+void omap_framebuffer_unpin(struct drm_framebuffer *fb);
 void omap_framebuffer_update_scanout(struct drm_framebuffer *fb,
 		struct omap_drm_window *win, struct omap_overlay_info *info);
 struct drm_connector *omap_framebuffer_get_next_connector(

drivers/gpu/drm/omapdrm/omap_fb.c

@@ -287,10 +287,10 @@ int omap_framebuffer_pin(struct drm_framebuffer *fb)
 }
 
 /* unpin, no longer being scanned out: */
-int omap_framebuffer_unpin(struct drm_framebuffer *fb)
+void omap_framebuffer_unpin(struct drm_framebuffer *fb)
 {
 	struct omap_framebuffer *omap_fb = to_omap_framebuffer(fb);
-	int ret, i, n = drm_format_num_planes(fb->pixel_format);
+	int i, n = drm_format_num_planes(fb->pixel_format);
 
 	mutex_lock(&omap_fb->lock);
 
@@ -298,24 +298,16 @@ int omap_framebuffer_unpin(struct drm_framebuffer *fb)
 
 	if (omap_fb->pin_count > 0) {
 		mutex_unlock(&omap_fb->lock);
-		return 0;
+		return;
 	}
 
 	for (i = 0; i < n; i++) {
 		struct plane *plane = &omap_fb->planes[i];
-		ret = omap_gem_put_paddr(plane->bo);
-		if (ret)
-			goto fail;
+		omap_gem_put_paddr(plane->bo);
 		plane->paddr = 0;
 	}
 
 	mutex_unlock(&omap_fb->lock);
-
-	return 0;
-
-fail:
-	mutex_unlock(&omap_fb->lock);
-	return ret;
 }
 
 struct drm_gem_object *omap_framebuffer_bo(struct drm_framebuffer *fb, int p)