fix: invalid macro variable in mp_lockanytable.sas

[allanbowe]

Issue

n/a

Intent

Fixing some recently discovered bugs

Implementation

Updates to:

• mf_existvar.sas
• mp_lockanytable.sas

A test is also included to cover the change in mf_existvar.sas

Checks

• [x] Code is formatted correctly (sasjs lint).
• [x] Any new functionality has been unit tested.
• [ ] All unit tests are passing (sasjs test).

[sasjsbot]

:tada: This PR is included in version 4.45.12 :tada:

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot :package::rocket: