Save stc temp logs in the stc folder

There was an issue when OCN was set to localhost. As part of Net-Smoke,
the command 'mn -c' is run which removes '/tmp/*.log'. This potentially
caused some tests to fail.

Change-Id: If68c184902b994e1ee38ea775c378ce29cdb891f
(cherry picked from commit a67dc45535c7b0b8ea6f246a10c1f2e4e18abb83)
diff --git a/tools/test/bin/onos-check-flows b/tools/test/bin/onos-check-flows
index ce80444..e3406ec 100755
--- a/tools/test/bin/onos-check-flows
+++ b/tools/test/bin/onos-check-flows
@@ -3,7 +3,7 @@
 # Checks ONOS summary data
 # -----------------------------------------------------------------------------
 
-aux=/tmp/stc-$$.log
+aux=/tmp/stc/stc-$$.log
 trap "rm -f $aux 2>/dev/null" EXIT
 
 for i in {1..6}; do