Update protectionPreRequisites For Use w/o CHATTR (#1716)

## Description
Update protectionPreRequisites For Use w/o CHATTR command available
Adds a return 0 if we reach eventually the end of the func.

## Where should the reviewer start?
cntools.sh -o w/o chattr and ENABLE_CHATTR false

## Motivation and context
cntools.sh -o w/o chattr and ENABLE_CHATTR false does not work
protectionPreRequisites returns non ZERO code if 
- ENABLE_CHATTR false
- chattr not available Because [ false == true ] (L139) will return a
non zero rc.

## Which issue it fixes?
n/a

## How has this been tested?
[cntools.sh -o w/o chattr and ENABLE_CHATTR false] is launching OK up to
the main menu.

scripts/cnode-helper-scripts/cntools.library

@@ -149,6 +149,7 @@ protectionPreRequisites() {
     fi
     rm -f "${TMP_DIR}"/test
   fi
+  return 0
 }
 
 # Command     : safeDel [path]