backends/drm: optimize cursor moves
Commit 1: cache the current thread, there's no need to look it up each time
Commit 2: wait on the condition variable when a pageflip is still pending, instead of effectively busy looping
Edited by Xaver Hugl
Commit 1: cache the current thread, there's no need to look it up each time
Commit 2: wait on the condition variable when a pageflip is still pending, instead of effectively busy looping