Do not attempt to search for local libpcap libraries lying around in the parent
of the build directory, or anywhere else random. This is not expected to
succeed anyway, but it is better to be sure.

diff -Naur arpwatch-3.1-original/configure arpwatch-3.1/configure
--- arpwatch-3.1-original/configure	2020-04-05 20:22:04.000000000 -0400
+++ arpwatch-3.1/configure	2020-11-07 11:59:40.114550004 -0500
@@ -5437,6 +5437,7 @@
     places=`ls .. | sed -e 's,/$,,' -e 's,^,../,' | \
 	egrep '/libpcap-[0-9]*\.[0-9]*(\.[0-9]*)?([ab][0-9]*)?$'`
     for dir in $places ../libpcap libpcap ; do
+	    break
 	    basedir=`echo $dir | sed -e 's/[ab][0-9]*$//'`
 	    if test $lastdir = $basedir ; then
 		    		    continue;