From: Svante Signell <svante.signell@gmail.com>

Currently shadow fails to build from source and is flagged as
out-of-date. This is due to a usage of PATH_MAX, which is not defined
on GNU/Hurd. The attached patch solves this problem by allocating a
fixed number of 32 bytes for the string proc_dir_name in files
src/procuidmap.c and src/procgidmap.c. (In fact only 18 bytes are
needed)

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>