This is the typical sequence of events:

1. The pilot finds a defect on the aircraft. They enter the details into the technical log.
2. The relevant work is done to fix or replace the broken part.
3. The maintenance release document is signed by the engineer to confirm that the work is complete and inspected.
4. The pilot now counter signs the maintenance release to accept the aircraft back into service.

In this question, the maintenance release has been signed before the work has been done. This is NOT the correct procedure. A new maintenance relase form is required, after inspection of the work to confirm that all was done in accordance with proper procedures. Here's more information from ICAO Annex 6...

Chapter 8 - Aeroplane Maintenance
8.8 Maintenance release

8.8.1 A maintenance release shall be completed and signed to certify that the maintenance work performed has been completed satisfactorily and in accordance with approved data and the procedures described in the maintenance organization’s procedures manual.

8.8.2 A maintenance release shall contain a certification including:

a) basic details of the maintenance carried out including detailed reference of the approved data used;
b) the date such maintenance was completed;
c) when applicable, the identity of the approved maintenance organization; and
d) the identity of the person or persons signing the release.