fix enter cros_sdk path

cros_enter_sdk.sh

@@ -4,14 +4,17 @@
 #
 _working_dir_name=$1
 
+_working_dir_name=$1
 if [ ${_working_dir_name: -1} = " " ]; then
     #somehow there's a space char when expect argument
     _working_dir_name=${_working_dir_name::-1}
 fi
 
+_mydir="$(pwd)"
+_parentdir="$(dirname "$_mydir")"
 _working_full_path="${_parentdir}/${_working_dir_name}"
 cd ${_working_full_path}
-echo "GOTO: ${_working_full_path}" 
+echo "working path ${_working_full_path}"
 
 echo 'cros_sdk --no-ns-pid'
 cros_sdk --no-ns-pid