scsi: qla2xxx: Fix uninitialized work element

Fixes following stack trace

kernel: Call Trace:
kernel: dump_stack+0x63/0x84
kernel: __warn+0xd1/0xf0
kernel: warn_slowpath_null+0x1d/0x20
kernel: __queue_work+0x37a/0x420
kernel: queue_work_on+0x27/0x40
kernel: queue_work+0x14/0x20 [qla2xxx]
kernel: schedule_work+0x13/0x20 [qla2xxx]
kernel: qla2x00_post_work+0xab/0xb0 [qla2xxx]
kernel: qla2x00_post_aen_work+0x3b/0x50 [qla2xxx]
kernel: qla2x00_async_event+0x20d/0x15d0 [qla2xxx]
kernel: ? lock_timer_base+0x7d/0xa0
kernel: qla24xx_intr_handler+0x1da/0x310 [qla2xxx]
kernel: qla2x00_poll+0x36/0x60 [qla2xxx]
kernel: qla2x00_mailbox_command+0x659/0xec0 [qla2xxx]
kernel: ? proc_create_data+0x7a/0xd0
kernel: qla25xx_init_rsp_que+0x15b/0x240 [qla2xxx]
kernel: ? request_irq+0x14/0x20 [qla2xxx]
kernel: qla25xx_create_rsp_que+0x256/0x3c0 [qla2xxx]
kernel: qla2xxx_create_qpair+0x2af/0x5b0 [qla2xxx]
kernel: qla2x00_probe_one+0x1107/0x1c30 [qla2xxx]

Fixes: ec7193e2 ("qla2xxx: Fix delayed response to command for loop mode/direct connect.")
Cc: <stable@vger.kernel.org> # 4.13
Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>