log/syslog: report errors from write Fixes issue 5541. This time for sure.
log/syslog: report errors from write
Fixes issue 5541.
This time for sure.

R=golang-dev, minux.ma, iant
CC=golang-dev
https://codereview.appspot.com/9668043

h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang