6rd: pass ipcalc as argument to eval

Instead of grepping for NETWORK after calling ipcalc.sh; pass ipcalc.sh as
argument to eval allowing to use $NETWORK to retrieve the IPv4 prefix
(ip4prefix).

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

package/network/ipv6/6rd/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=6rd
 PKG_VERSION:=9
-PKG_RELEASE:=3
+PKG_RELEASE:=4
 PKG_LICENSE:=GPL-2.0
 
 include $(INCLUDE_DIR)/package.mk

package/network/ipv6/6rd/files/6rd.sh

@@ -40,8 +40,8 @@ proto_6rd_setup() {
 
 	# Determine the relay prefix.
 	local ip4prefixlen="${ip4prefixlen:-0}"
-	local ip4prefix=$(ipcalc.sh "$ipaddr/$ip4prefixlen" | grep NETWORK)
-	ip4prefix="${ip4prefix#NETWORK=}"
+	local ip4prefix
+	eval "$(ipcalc.sh "$ipaddr/$ip4prefixlen")";ip4prefix=$NETWORK
 
 	# Determine our IPv6 address.
 	local ip6subnet=$(6rdcalc "$ip6prefix/$ip6prefixlen" "$ipaddr/$ip4prefixlen")