Fixed "undefined reference to makedev"

[theverygaming]

Fixed

mailbox.o: In function `mbox_open':
mailbox.c:(.text+0xc54): undefined reference to `makedev'
mailbox.c:(.text+0xcbc): undefined reference to `makedev'

[rexington]

This worked for me on Buster.

[Techwolf12]

Worked for me as well, thanks!