drm: Fix 32-bit drmSyncobjWait.

Otherwise we get an EFAULT, at least on a 64-bit kernel.

Fixes: 2048a9e7 "drm: add drmSyncobjWait wrapper"
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>

xf86drm.c

@@ -4271,7 +4271,7 @@ int drmSyncobjWait(int fd, uint32_t *handles, unsigned num_handles,
     int ret;
 
     memclear(args);
-    args.handles = (intptr_t)handles;
+    args.handles = (uintptr_t)handles;
     args.timeout_nsec = timeout_nsec;
     args.count_handles = num_handles;
     args.flags = flags;