scsi: qla2xxx: Fix recursion while sending terminate exchange

commit 3efc31f7 upstream.

During error test case where switch port status is toggled from enable to
disable, following stack trace is seen which indicates recursion trying to
send terminate exchange.  This regression was introduced by commit
82de802a ("scsi: qla2xxx: Preparation for Target MQ.")

BUG: stack guard page was hit at ffffb96488383ff8 (stack is ffffb96488384000..ffffb96488387fff)
BUG: stack guard page was hit at ffffb964886c3ff8 (stack is ffffb964886c4000..ffffb964886c7fff)
kernel stack overflow (double-fault): 0000 [#1] SMP
qlt_term_ctio_exchange+0x9c/0xb0 [qla2xxx]
qlt_term_ctio_exchange+0x9c/0xb0 [qla2xxx]
qlt_term_ctio_exchange+0x9c/0xb0 [qla2xxx]
qlt_term_ctio_exchange+0x9c/0xb0 [qla2xxx]
qlt_term_ctio_exchange+0x9c/0xb0 [qla2xxx]

Fixes: 82de802a ("scsi: qla2xxx: Preparation for Target MQ.")
Cc: <stable@vger.kernel.org> #4.10
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>