ports/72182: fix bsd.port.mk for different semantics of -b in BSD and GNU diff

[Mark Linimon]

Synopsis: fix bsd.port.mk for different semantics of -b in BSD and GNU diff

Responsible-Changed-From-To: freebsd-ports-bugs->portmgr
Responsible-Changed-By: linimon
Responsible-Changed-When: Thu Sep 30 03:27:04 GMT 2004
Responsible-Changed-Why: 
bsd.*.mk-related.

http://www.freebsd.org/cgi/query-pr.cgi?pr=72182