forgot a piece of debugging in previous change
forgot a piece of debugging
in previous change

R=rsc
http://go/go-review/1017052

apparentlymart/golang,gnanderson/go,h8liu/golang,apparentlymart/golang,h8liu/golang,gnanderson/go,nightlyone/golang,dsriram/golang,tianon/debian-golang,apparentlymart/golang,pombredanne/go-deleteme,tv42/old-go,tv42/old-go,apparentlymart/golang,nightlyone/golang,pombredanne/go-deleteme,tianon/debian-golang,tianon/debian-golang,ssrl/go,bdwalton/debian-golang,dsriram/golang,h8liu/golang,bdwalton/debian-golang,gnanderson/go,bdwalton/debian-golang,bdwalton/debian-golang,pombredanne/go-deleteme,apparentlymart/golang,apparentlymart/golang,h8liu/golang,gnanderson/go,tianon/debian-golang,gnanderson/go,ssrl/go,dsriram/golang,h8liu/golang,h8liu/golang,pombredanne/go-deleteme,nightlyone/golang,bdwalton/debian-golang,ssrl/go,pombredanne/go-deleteme,tianon/debian-golang,nightlyone/golang,bdwalton/debian-golang,dsriram/golang,tv42/old-go,gnanderson/go,bdwalton/debian-golang,tianon/debian-golang,dsriram/golang,apparentlymart/golang,pombredanne/go-deleteme,dsriram/golang,tv42/old-go,nightlyone/golang,nightlyone/golang,bdwalton/debian-golang,h8liu/golang,ssrl/go,tianon/debian-golang,dsriram/golang,ssrl/go,ssrl/go,tv42/old-go,pombredanne/go-deleteme,tianon/debian-golang,tv42/old-go,gnanderson/go,nightlyone/golang,tv42/old-go,ssrl/go