Don't try to enumerate excluded files. List included files, and remove names
from the list if they match an excluded-file pattern.
This resolves the problem that the script could get into an infinite loop
due to the use of recursive globbing. Unfortunately, Python's recursive
globs follows symbolic links to directories, which leads to an infinite loop
if a symbolic link points to an ancestor of the directory that contains it.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>