Make iproute2 configure script more flexible

On Arch Linux, we still install the iptables shared libraries in
/usr/lib/iptables/, even though the main library is installed to
/usr/lib/libxtables.so. This change checks all available locations to
correctly find the iptables library directory.
Signed-off-by: Dan McGee <dan@archlinux.org>

configure

@@ -3,8 +3,6 @@
 #
 INCLUDE=${1:-"$PWD/include"}
 
-TABLES=
-
 check_atm()
 {
 cat >/tmp/atmtest.c <<EOF
@@ -141,9 +139,6 @@ check_ipt()
 	if ! grep TC_CONFIG_XT Config > /dev/null
 	then
 		echo "using iptables"
-		TABLES="iptables"
-	else
-		TABLES="xtables"
 	fi
 }
 
@@ -152,10 +147,10 @@ check_ipt_lib_dir()
 	IPT_LIB_DIR=""
 	for dir in /lib /usr/lib /usr/local/lib
 	do
-		for file in $dir/$TABLES/lib*t_*so ; do
+		for file in $dir/{xtables,iptables}/lib*t_*so ; do
 			if [ -f $file ]; then
-				echo $dir/$TABLES
-				echo "IPT_LIB_DIR:=$dir/$TABLES" >> Config
+				echo ${file%/*}
+				echo "IPT_LIB_DIR:=${file%/*}" >> Config
 				return
 			fi
 		done