firewire-lib: minor code modification for blacket in if statement
bebob: change prototype for snd_bebob_read_xxx()

In following commit, snd_bebob_maudio_load_firmware() will use this function
to check model date.
bebob: check software version when loading firmware for M-Audio models

This driver sends a cue to load firmware for M-Audio models with firmware
version 5058 or later. To confirm its firmware version, this commit adds
checking the date of software used to build.