[SCSI] libfc: Fix compilation warnings with allmodconfig

When building with a .config generated from 'make allmodconfig'
some build warnings are generated. This patch corrects the warnings,
adds a FC_FID_NONE (= 0) enumeration for FC-IDs and cleans up one
variable naming to meet our variable naming conventions. For example,
fc_lport's should be named "lport," not "lp."

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>