libxml2: do not apply libtool patch when compiling for host

The libtool patch is not applied when building for the target because
it does not apply, so do not attempt to apply it when building for the
host. This fixes libxml2 build for the host.

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

package/libxml2/libxml2.mk

@@ -28,6 +28,8 @@ HOST_LIBXML2_CONF_OPT = \
 		--enable-shared --without-debugging --without-python \
 		--without-threads
 
+HOST_LIBXML2_LIBTOOL_PATCH = NO
+
 $(eval $(call AUTOTARGETS,package,libxml2))
 $(eval $(call AUTOTARGETS,package,libxml2,host))