[SCSI] zfcp: Shorten excessive names in debug trace.

Saving on line breaks, improving readability, by shortening excessive
function names and identifiers, by simplifying some functions call
chains, and by simplifying nesting of some data structure.

Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>