qdoc: Fixed incorrect href attribute values in qdoc

qdoc: Fixed incorrect href attribute values in qdoc

There were two fileBase() functions, but only one
was correct. The wrong one was being called in some
cases. Now there is only one fileBase() function,
which is always called.

Task nr: QTBUG-26591

Change-Id: I2c40e2152a8c7ad1bb9db256ecf1367148f0e7f6
Reviewed-by: Casper van Donderen <casper.vandonderen@nokia.com>