Fix a panic in blk_mq_hctx_has_pending() that is caused by a racy call to
blk_mq_run_hw_queues in a dasd function that might get called with the
request queue not yet initialized during initialization.
Signed-off-by: NStefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>