[SCSI] libfc: bug in erroring out upon FCP_RSP_LEN_VAL in fc_fcp_resp

fc_fcp_resp is assuming when FCP_SNS_LEN_VAL is set, the FCP_RSP_LEN_VAL
is not, which is not true. This leads to not copying the sense data and
error out a valid FCP_RSP.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>