remove injection of default_pre in infile()/$$fromfile()

remove injection of default_pre in infile()/$$fromfile()

this is a hack from the times when these functions were (ab)used to
inspect proper project files, but the inclusion was done with a clean
project, so that the included files did not have any functions to work
with.

Change-Id: I19925e8ead597ca38df040000c183e368b32c06d
Reviewed-by: Joerg Bornemann <joerg.bornemann@nokia.com>