math/gnuplot-tex-extras: Remove commented texmf

After 6 months of commit there were no comments from the maintainer or
any bugs reported about the removal of texmf which means this port
does not use texmf at all.

Sponsored by:	Nepustil
Approved by:    portmgr (blanket)

math/gnuplot-tex-extras/Makefile

@@ -12,7 +12,6 @@ WWW=		http://www.gnuplot.info/
 RUN_DEPENDS=	gnuplot:math/gnuplot
 
 USES=		cpe tex
-#USE_TEX=	texmf
 NO_BUILD=	yes
 PLIST_FILES=	${TEX_FILES:S,^,${TEX_DIR}/,}