banhosts: Call killall with the -s

Some versions of killall do support the `killall -SIGNAL` syntax and
have only `-s SIGNAL` which should be supported everywhere.

I see the problem with *killall (PSmisc) 23.3* on latest TurrisOS 5.2

Signed-off-by: Jan Baier <jan.baier@amagical.net>

utils/banhosts/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=banhostlist
 PKG_VERSION:=1
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_BUILD_DIR=$(BUILD_DIR)/$(PKG_NAME)-$(PKG_VERSION)
 PKG_MAINTAINER:=Matteo Croce <matteo@openwrt.org>

utils/banhosts/files/updatebanhost

@@ -6,7 +6,7 @@ gethosts() {
 	logger -t "banhost[$$]" "Update $file"
 	wget -qO- http://winhelp2002.mvps.org/hosts.txt |awk 'BEGIN{printf "0.0.0.0"}/^0\.0\.0\.0/{printf " "$2}END{exit(!FNR)}' >$file || exit 1
 	echo -n $time >$file.time
-	exec killall -HUP dnsmasq
+	exec killall -s HUP dnsmasq
 }
 
 if [ "$ACTION" = ifup -a "$INTERFACE" = wan ]; then