test: use ss -lx instead of netstat by default

netstat is deprecated on CentOS/RHEL in favor of
iproute utilities.  At least on one of the systems
in our test pool, netstat isn't installed - we could
install it but let's instead try to use ss if it's
available and still fall back to netstat when it's
not.

While here, remove waitforlisten_tcp instead of
changing it to use ss.  We are not using waitforlisten_tcp
anywhere and do not recommend enabling RPC over TCP except
for test purposes.

Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: I4ee3597536797f501750915a4a219b55004bd454

Reviewed-on: https://review.gerrithub.io/406464
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>

test/common/autotest_common.sh

@@ -233,32 +233,15 @@ function waitforlisten() {
 		if ! kill -s 0 $1; then
 			exit 1
 		fi
+		if hash ss; then
+			if ss -lx | grep -q $rpc_addr; then
+				ret=0
+			fi
+		else
+			# if system doesn't have ss, just assume it has netstat
 			if netstat -an -x | grep -iw LISTENING | grep -q $rpc_addr; then
 				ret=0
 			fi
-	done
-	set -x
-}
-
-function waitforlisten_tcp() {
-	# $1 = process pid
-	# $2 = TCP port number
-	if [ -z "$1" ] || [ -z "$2" ]; then
-		exit 1
-	fi
-
-	echo "Waiting for process to start up and listen on TCP port $2..."
-	# turn off trace for this loop
-	set +x
-	ret=1
-	while [ $ret -ne 0 ]; do
-		# if the process is no longer running, then exit the script
-		#  since it means the application crashed
-		if ! kill -s 0 $1; then
-			exit
-		fi
-		if netstat -an --tcp | grep -iw listen | grep -q $2; then
-			ret=0
 		fi
 	done
 	set -x