selftests: mptcp: clean tmp files in simult_flows

'$cin' and '$sin' variables are local to a function: they are then not
available from the cleanup trap.

Instead, we need to use '$large' and '$small' that are not local and
defined just before setting the trap.

Without this patch, running this script in a loop might cause a:

  write: No space left on device

issue.

Fixes: 1a418cb ("mptcp: simult flow self-tests")
Acked-by: Paolo Abeni <[email protected]>
Signed-off-by: Matthieu Baerts <[email protected]>
Signed-off-by: Mat Martineau <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>

Author: matttbe

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

@@ -22,8 +22,8 @@ usage() {
 
 cleanup()
 {
-	rm -f "$cin" "$cout"
-	rm -f "$sin" "$sout"
+	rm -f "$cout" "$sout"
+	rm -f "$large" "$small"
 	rm -f "$capout"
 
 	local netns