odhcpd: remove bogus IPKG_INSTROOT reference

IPKG_INSTROOT is only set under image builder and we won't be running
this script at build time either, so remove the reference before it gets
cargo-culted into other scripts.

Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
Acked-by: Hans Dedecker <dedeckeh@gmail.com>

package/network/services/odhcpd/Makefile

@@ -8,7 +8,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=odhcpd
-PKG_RELEASE:=3
+PKG_RELEASE:=4
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL=$(PROJECT_GIT)/project/odhcpd.git

package/network/services/odhcpd/files/odhcpd-update

@@ -1,6 +1,6 @@
 #!/bin/sh
 # Make dnsmasq reread hostfile by sending SIGHUP signal
 
-. $IPKG_INSTROOT/lib/functions/procd.sh
+. /lib/functions/procd.sh
 
 procd_send_signal dnsmasq