[sheepdog] rename printf functions

[MORITA Kazutaka]

At Wed, 7 Aug 2013 17:04:29 +0800,
Liu Yuan wrote:
> 
> On Wed, Aug 07, 2013 at 05:44:53PM +0900, MORITA Kazutaka wrote:
> > Hi all,
> > 
> > 1. How about introducing the following functions?
> > 
> >    sd_emerg()  to log message with log level SDOG_EMERG
> >    sd_alert()  to log message with log level SDOG_ALERT
> >    sd_crit()   to log message with log level SDOG_CRIT
> >    sd_err()    to log message with log level SDOG_ERR
> >                (sd_eprintf will be removed)
> 
> sd_error() looks more consistent with others.

I've looked into linux kernel codes, but xxx_err looks more common to
print message with a LOG_ERR level, doesn't it?
E.g. pr_err(), xfs_err(), dev_err(), ...

Thanks,

Kazutaka