- Use syslog(..., "...%m") instead of syslog(..., "...%s",
strerror(errno)).
- Don't put a simple and single statement into a block.
- Indent continuation line by four space.
- Add an empty line at the beginning of a function if it doesn't have
local variable.
- Use err() or errx() instead of fprintf(stderr, "progname: ....\n")
and exit() (there was two place left).
- Use MOUNT_PORTAL, which is defined as "portal" in sys/mount.h,
instead of using "portal" directly.
- Fold long line to fit column < 80.
