drm: rename dev->count_lock to dev->buf_lock

Since really that's all it protects - legacy horror stories in
drm_bufs.c. Since I don't want to waste any more time on this I didn't
bother to actually look at what it protects in there, but it's at
least contained now.

v2: Move the spurious hunk to the right patch (Thierry).

Cc: Thierry Reding <thierry.reding@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

include/drm/drmP.h

@@ -1069,7 +1069,6 @@ struct drm_device {
 
 	/** \name Locks */
 	/*@{ */
-	spinlock_t count_lock;		/**< For inuse, drm_device::open_count, drm_device::buf_use */
 	struct mutex struct_mutex;	/**< For others */
 	struct mutex master_mutex;      /**< For drm_minor::master and drm_file::is_master */
 	/*@} */
@@ -1077,6 +1076,7 @@ struct drm_device {
 	/** \name Usage Counters */
 	/*@{ */
 	int open_count;			/**< Outstanding files open, protected by drm_global_mutex. */
+	spinlock_t buf_lock;		/**< For drm_device::buf_use and a few other things. */
 	int buf_use;			/**< Buffers in use -- cannot alloc */
 	atomic_t buf_alloc;		/**< Buffer allocation in progress */
 	/*@} */