drm/i915/perf: Treat u64 in uabi as a normal integer

Forgo marking up the u64 integer representing a user pointer as this
just annoys sparse. The conversion from u64 to a user pointer is managed
by u64_to_user_ptr().

Fixes: eec688e1 ("drm/i915: Add i915 perf infrastructure")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Robert Bragg <robert@sixbynine.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161130164649.26809-1-chris@chris-wilson.co.ukReviewed-by: Matthew Auld <matthew.auld@intel.com>

include/uapi/drm/i915_drm.h

@@ -1292,7 +1292,7 @@ struct drm_i915_perf_open_param {
 	 * Pointer to array of u64 (id, value) pairs configuring the stream
 	 * to open.
 	 */
-	__u64 __user properties_ptr;
+	__u64 properties_ptr;
 };
 
 /**