libvorbis: fix LIBVORBIS_SITE

The LIBVORBIS_SITE included a reference to $(LIBVORBIS-SOURCE), which
doesn't exist. And anyway was useless because the <pkg>_SITE variable
should not contain the name of the tarball.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/libvorbis/libvorbis.mk

@@ -6,7 +6,7 @@
 
 LIBVORBIS_VERSION = 1.3.3
 LIBVORBIS_SOURCE = libvorbis-$(LIBVORBIS_VERSION).tar.gz
-LIBVORBIS_SITE = http://downloads.xiph.org/releases/vorbis/$(LIBVORBIS-SOURCE)
+LIBVORBIS_SITE = http://downloads.xiph.org/releases/vorbis/
 LIBVORBIS_INSTALL_STAGING = YES
 LIBVORBIS_CONF_OPT = --disable-oggtest
 LIBVORBIS_DEPENDENCIES = host-pkgconf libogg