perl-xml-parser: fix build

(missing when changing the naming scheme of Perl modules)

Signed-off-by: Francois Perrad <francois.perrad@gadz.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/perl-xml-parser/perl-xml-parser.mk

@@ -10,7 +10,7 @@ PERL_XML_PARSER_SITE = $(BR2_CPAN_MIRROR)/authors/id/T/TO/TODDR/
 PERL_XML_PARSER_DEPENDENCIES = expat
 PERL_XML_PARSER_LICENSE = Artistic or GPLv1+
 
-HOST_LIBXML_PARSER_PERL_CONF_OPT = \
+HOST_PERL_XML_PARSER_CONF_OPT = \
 	EXPATLIBPATH=$(HOST_DIR)/usr/lib \
 	EXPATINCPATH=$(HOST_DIR)/usr/include