oacc-init.c (acc_shutdown_1): Call gomp_mutex_unlock for goacc_thread_lock on error paths.

	* oacc-init.c (acc_shutdown_1): Call gomp_mutex_unlock for
	goacc_thread_lock on error paths.
	* oacc-mem.c (lookup_host): Remove locking from function. Note
	locking requirement for caller in function comment.
	(lookup_dev): Likewise.
	(acc_free, acc_deviceptr, acc_hostptr, acc_is_present)
	(acc_map_data, acc_unmap_data, present_create_copy, delete_copyout)
	(update_dev_host, gomp_acc_insert_pointer, gomp_acc_remove_pointer):
	Add locking.

From-SVN: r222860