Redundant format arg in resolveFilePathRelativeToBuildFileDirectory

Summary:
In method resolveFilePathRelativeToBuildFileDirectory, String.format
is called with 3 arguments, but the string format only expects 2.

Remove the redundant one.

Test Plan:
Run some test builds.

Change-Id: If284a8c5cf0c6b00e6a65f68181e4dc803e00b57