target: Set response format in INQUIRY response

commit ce136176 upstream.

Current SCSI specs say that the "response format" field in the standard
INQUIRY response should be set to 2, and all the real SCSI devices I
have do put 2 here.  So let's do that too.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>