Small fixes to onos-buck

Change-Id: I3b1afc4745b7d6a0bbdb1863cb9ab6240e70a123
diff --git a/tools/build/onos-buck b/tools/build/onos-buck
index 8923578..cf896bb 100755
--- a/tools/build/onos-buck
+++ b/tools/build/onos-buck
@@ -27,9 +27,9 @@
         echo "SHA cannot be verified"
     fi
     chmod 555 ./buck
-    echo $(./buck -V 2>/dev/null) > .buck_version
+    echo $(./buck --version 2>/dev/null) > .buck_version
     chmod 444 .buck_version
-    rm -rf ./buck_out
+    rm -rf ./buck-out
     printf "Successfully downloaded Buck to $ONOS_ROOT/bin/buck\n\n"
 fi
 popd > /dev/null