MFC r316993, r316994, r316997 as follows:

MFC r316993, r316994, r316997 as follows:

r316993:

Fix CID 1372601 in ipfilter/lib/parsefields.c, possible NULL pointer
dereference should reallocarray() fail.

	Reported by:	Coverity CID 1372601

r316994:

Fix CID 1372600 in ipfilter/tools/ipf_y.y, possible NULL pointer
dereference should reallocarray() fail.

	Reported by:	Coverity CID 1372600

r316997:

Use warnx() to issue error message.

	Reported by:	cem

git-svn-id: svn://svn.freebsd.org/base/stable/10@317314 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f