panfrost: Avoid double unlock.
Fix defect reported by Coverity Scan.
Double unlock (LOCK) double_unlock: pthread_mutex_unlock unlocks dev->indirect_draw_shaders.lock while it is unlocked.
Fixes: 2e6d94c1 ("panfrost: Add helpers to support indirect draws") Signed-off-by: Vinson Lee vlee@freedesktop.org