compress uses setfile() to make flags, ownership and mode of the output
the same as those of the original. However, if the filesystem holding the
output file doesn't support these operations, compress prints a warning.
This bites a bit with NFS directories, which always fail the chflags()
operation. If the file system doesn't support the operation, then the
flags data wasn't valid on the original file anyway, so the warning is
spurious.
Submitted by: bin/16981 (Peter Edwards <peter.edwards@ireland.com>)
