Make vcldir downstream-friendly in etc/Makefile.am

And sync bin/varnishd/Makefile.am to use the same (and more accurate)
variable name.

Spotted by Reza.

bin/varnishd/Makefile.am

@@ -145,14 +145,14 @@ nobase_pkginclude_HEADERS = \
 	cache/cache_filter.h \
 	waiter/waiter.h
 
-pkgdatadir = ${datarootdir}/${PACKAGE}/vcl
+vcldir=$(datarootdir)/$(PACKAGE)/vcl
 
 varnishd_CFLAGS = \
 	@PCRE_CFLAGS@ \
 	@SAN_CFLAGS@ \
 	-DVARNISH_STATE_DIR='"${VARNISH_STATE_DIR}"' \
 	-DVARNISH_VMOD_DIR='"${pkglibdir}/vmods"' \
-	-DVARNISH_VCL_DIR='"${pkgsysconfdir}:${pkgdatadir}"'
+	-DVARNISH_VCL_DIR='"${pkgsysconfdir}:${vcldir}"'
 
 varnishd_LDFLAGS = -export-dynamic
 

etc/Makefile.am

@@ -11,6 +11,6 @@ New users is recommended to use the example.vcl file as a starting point.\n\n";\
 	sed -n '/vcl_recv/,$$p' $(top_srcdir)/bin/varnishd/builtin.vcl ) | \
 	sed 's/^\(.*\)$$/# \1/' > builtin.vcl
 
-vcldir=$(datarootdir)/varnish/vcl
+vcldir=$(datarootdir)/$(PACKAGE)/vcl
 
 dist_vcl_DATA = devicedetect.vcl