fix redundant searches in FindObjectFile, if the object was found on the first try

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24725 3ad0048d-3df7-0310-abae-a5850022a9f2
handle the cases where f contains an absolute path

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24726 3ad0048d-3df7-0310-abae-a5850022a9f2