quagga: set ac_cv_path_PERL to '/usr/bin/env perl'

Set ac_cv_path_PERL to '/usr/bin/env perl' to fix problem when
/path/to/hosttools/perl is longer than 128.

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Joe MacDonald <joe_macdonald@mentor.com>

meta-networking/recipes-protocols/quagga/quagga.inc

@@ -70,6 +70,8 @@ EXTRA_OECONF = "--sysconfdir=${sysconfdir}/quagga \
                 ap_cv_cc_pie=no \
                 ${SNMP_CONF}"
 
+CACHED_CONFIGUREVARS += "ac_cv_path_PERL='/usr/bin/env perl'"
+
 do_install () {
     # Install init script and default settings
     install -m 0755 -d ${D}${sysconfdir}/default ${D}${sysconfdir}/init.d \