package/ssdp-responder: fix misspelled define directive

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/ssdp-responder/ssdp-responder.mk

@@ -25,7 +25,7 @@ define SSDP_RESPONDER_INSTALL_INIT_SYSV
 		$(TARGET_DIR)/etc/init.d/S50ssdpd
 endef
 
-define SSDP-RESPONDER_INSTALL_INIT_SYSTEMD
+define SSDP_RESPONDER_INSTALL_INIT_SYSTEMD
 	$(INSTALL) -D -m 644 $(@D)/ssdp-responder.service \
 		$(TARGET_DIR)/usr/lib/systemd/system/ssdp-responder.service
 endef