[SCSI] zfcp: dead code removal

Get rid of unused function zfcp_fsf_get_req and corresponding
prototype definition.

Commit a54ca0f6 in v2.6.28
"[SCSI] zfcp: Redesign of the debug tracing for HBA records."
accidentally introduced this code which was dead in the first place.

Signed-off-by: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>