libxslt: tell ./configure where libxml is

libxslt is currently configured with --with-libxml-include-prefix,
which allows libxslt ./configure to find libxml headers. However, the
build of libxslt fails because it doesn't find the library itself.

Therefore, instead of using --with-libxml-include-prefix, we switch to
the more generic --with-libxml-prefix.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/libxslt/libxslt.mk

@@ -21,7 +21,7 @@ LIBXSLT_CONF_OPT = --with-gnu-ld --enable-shared \
 		$(DISABLE_NLS) $(DISABLE_IPV6) \
 		--without-debugging --without-python \
 		--without-threads \
-		--with-libxml-include-prefix=$(STAGING_DIR)/usr/include/libxml2
+		--with-libxml-prefix=$(STAGING_DIR)/usr/
 
 LIBXSLT_DEPENDENCIES = uclibc $(LIBXSLT_DEPENDENCIES_EXTRA)