pkg-perl: fix previous commit

there is no variable PERL_INSTALL_NAME in master

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

package/pkg-perl.mk

@@ -102,7 +102,7 @@ define $(2)_CONFIGURE_CMDS
 			LD="$$(TARGET_CC)" \
 			LDDLFLAGS="-shared $$(TARGET_LDFLAGS)" \
 			LDFLAGS="$$(TARGET_LDFLAGS)" \
-			PERL_INC=$$(STAGING_DIR)/usr/lib/$$(PERL_INSTALL_NAME)/$$(PERL_VERSION)/$$(PERL_ARCHNAME)/CORE \
+			PERL_INC=$$(STAGING_DIR)/usr/lib/perl5/$$(PERL_VERSION)/$$(PERL_ARCHNAME)/CORE \
 			DESTDIR=$$(TARGET_DIR) \
 			INSTALLDIRS=vendor \
 			INSTALLVENDORLIB=/usr/lib/perl5/site_perl/$$(PERL_VERSION) \