This patch does the fallowing cleanup for
drivers/i2c/i2c-dev.c::i2c_dev_init():
*) in a error condition, return the error code of register_chrdev()
insted of -EIO;
*) adds missing audit for class_register();
*) in a error condition, only prints "Driver Initialisation Failed",
insted printing the cause. (Note that the error will be printed by
the return of the error code, and the information about what function
caused the problem need to be done by a debug code).