configure: correctly do some DPDK checks.

Add $DPDK_LIBS, not $DPDK_LDFLAGS, to $LIBS.

(cherry picked from commit 21dfd4a6fb560ff22ede82f3481f705dadfcfc3f)
diff --git a/configure b/configure
index cb57fba..ad99101 100755
--- a/configure
+++ b/configure
@@ -12118,7 +12118,7 @@
 	save_LIBS="$LIBS"
 	save_LDFLAGS="$LDFLAGS"
 	CFLAGS="$CFLAGS $DPDK_CFLAGS"
-	LIBS="$LIBS $DPDK_LDFLAGS"
+	LIBS="$LIBS $DPDK_LIBS"
 	LDFLAGS="$LDFLAGS $DPDK_LDFLAGS"
 
 	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether we can compile the DPDK support" >&5
@@ -12194,7 +12194,7 @@
 
 	if test "$ac_cv_func_rte_eth_dev_count_avail" = yes; then
 		CFLAGS="$CFLAGS $DPDK_CFLAGS"
-		LIBS="$LIBS $DPDK_LDFLAGS"
+		LIBS="$LIBS $DPDK_LIBS"
 		LDFLAGS="$LDFLAGS $DPDK_LDFLAGS"
 		V_INCLS="$V_INCLS $DPDK_CFLAGS"
 
diff --git a/configure.ac b/configure.ac
index 78851ec..cefb5b3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2601,7 +2601,7 @@
 	save_LIBS="$LIBS"
 	save_LDFLAGS="$LDFLAGS"
 	CFLAGS="$CFLAGS $DPDK_CFLAGS"
-	LIBS="$LIBS $DPDK_LDFLAGS"
+	LIBS="$LIBS $DPDK_LIBS"
 	LDFLAGS="$LDFLAGS $DPDK_LDFLAGS"
 
 	AC_MSG_CHECKING(whether we can compile the DPDK support)
@@ -2649,7 +2649,7 @@
 
 	if test "$ac_cv_func_rte_eth_dev_count_avail" = yes; then
 		CFLAGS="$CFLAGS $DPDK_CFLAGS"
-		LIBS="$LIBS $DPDK_LDFLAGS"
+		LIBS="$LIBS $DPDK_LIBS"
 		LDFLAGS="$LDFLAGS $DPDK_LDFLAGS"
 		V_INCLS="$V_INCLS $DPDK_CFLAGS"
 		AC_DEFINE(PCAP_SUPPORT_DPDK, 1, [target host supports DPDK])