selftests: mptcp: join: do_transfer: reduce code dup

The same extra long command is present twice, with one small different:
the var for the stdin file is different.

Use a new dedicated var in one command to avoid this code duplication.

Signed-off-by: Matthieu Baerts (NGI0) <[email protected]>

Author: matttbe

tools/testing/selftests/net/mptcp/mptcp_join.sh

@@ -951,6 +951,7 @@ do_transfer()
 	local FAILING_LINKS=${FAILING_LINKS:-""}
 	local fastclose=${fastclose:-""}
 	local speed=${speed:-"fast"}
+	local in="${sin}"
 	port=$(get_port)
 
 	:> "$cout"
@@ -999,16 +1000,12 @@ do_transfer()
 
 	extra_srv_args="$extra_args $extra_srv_args"
 	if [ "$test_linkfail" -gt 1 ];then
-		timeout ${timeout_test} \
-			ip netns exec ${listener_ns} \
-				./mptcp_connect -t ${timeout_poll} -l -p $port -s ${srv_proto} \
-					$extra_srv_args "::" < "$sinfail" > "$sout" &
-	else
-		timeout ${timeout_test} \
-			ip netns exec ${listener_ns} \
-				./mptcp_connect -t ${timeout_poll} -l -p $port -s ${srv_proto} \
-					$extra_srv_args "::" < "$sin" > "$sout" &
+		in="${sinfail}"
 	fi
+	timeout ${timeout_test} \
+		ip netns exec ${listener_ns} \
+			./mptcp_connect -t ${timeout_poll} -l -p ${port} -s ${srv_proto} \
+				${extra_srv_args} "::" < "${in}" > "${sout}" &
 	local spid=$!
 
 	mptcp_lib_wait_local_port_listen "${listener_ns}" "${port}"