canonicalize: in CAN_ALL_BUT_LAST, allow trailing slash Coreutils' `readlink -f foo/' should not fail if lstat("foo") gives ENOENT. * lib/canonicalize.c (canonicalize_filename_mode): Skip trailing slashes when checking if last component is missing. * tests/test-canonicalize.c (main): Test this. Signed-off-by: Eric Blake <ebb9@byu.net>