cthon.zsh: Don't return 0 if one of the tests fails

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

cthon.zsh

@@ -41,6 +41,7 @@ for vers in $VERSION; do
 	ARGS+=("--version $vers")
 done
 
+ret=0
 set +e
 date | python -u $COLOR
 for test in $TESTS; do
@@ -50,5 +51,8 @@ for test in $TESTS; do
 				     --mountpoint ${MOUNTPOINT[-1]} \
 				     --user $USER --mntopt sec=$sec \
 				       $test $ARGS | python -u $COLOR
+		ret=$((ret+$?))
 	done
 done
+
+exit $ret