block/iscsi: fix deadlock on scsi check condition

block/iscsi: fix deadlock on scsi check condition

the retry logic was broken because the complete status
of the task structure was not reset. this resulted in
an infinite loop retrying the command over and over.

CC: qemu-stable@nongnu.org
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 837c390137193e715fee20b35c0ddb164b1c4fa4)

Conflicts:
	block/iscsi.c

*only modified retry clauses present before 063c3378

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>