ipkg doesn't like underscores in package names

But as there are packages with names containing them, and other package
managers probably have less problems with that, fix this issue at the
most specific place.

mk/package.mk

@@ -160,7 +160,7 @@ IDEPEND_$(1):=	$$(strip $(4))
 _ALL_CONTROLS+=	$$(IDIR_$(1))/CONTROL/control
 ICONTROL_$(1)?=	$(WRKDIR)/.$(2).control
 $$(IDIR_$(1))/CONTROL/control: ${_PATCH_COOKIE}
-	@echo "Package: $(2)" > $(WRKDIR)/.$(2).control
+	@echo "Package: $$(shell echo $(2) | tr '_' '-')" > $(WRKDIR)/.$(2).control
 	@echo "Section: $(6)" >> $(WRKDIR)/.$(2).control
 	@echo "Description: $(5)" >> $(WRKDIR)/.$(2).control
 	${BASH} ${SCRIPT_DIR}/make-ipkg-dir.sh $${IDIR_$(1)} $${ICONTROL_$(1)} $(3) ${CPU_ARCH}
@@ -177,7 +177,7 @@ $$(IDIR_$(1))/CONTROL/control: ${_PATCH_COOKIE}
 			comma=", "; \
 			last=$$$$dep; \
 		done; \
-		echo "Depends: $$$$deps" >>$${IDIR_$(1)}/CONTROL/control; \
+		echo "Depends: $$$$deps" | tr '_' '-' >>$${IDIR_$(1)}/CONTROL/control; \
 	fi
 	@for file in conffiles preinst postinst prerm postrm; do \
 		[ ! -f ./files/$(2).$$$$file ] || cp ./files/$(2).$$$$file $$(IDIR_$(1))/CONTROL/$$$$file; \