cups-filters: fix avahi dependency

avahi support requires avahi-client, which needs avahi-daemon and dbus

Fixes:
 - http://autobuild.buildroot.net/results/5c326bb56199000eb0e53a4d0f3c6c13be71cda0

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/cups-filters/cups-filters.mk

@@ -40,7 +40,8 @@ else
 CUPS_FILTERS_CONF_OPTS += --disable-dbus
 endif
 
-ifeq ($(BR2_PACKAGE_AVAHI),y)
+# avahi support requires avahi-client, which needs avahi-daemon and dbus
+ifeq ($(BR2_PACKAGE_AVAHI_DAEMON)$(BR2_PACKAGE_DBUS),yy)
 CUPS_FILTERS_DEPENDENCIES += avahi
 CUPS_FILTERS_CONF_OPTS += --enable-avahi
 else