godefs: avoid gcc 4'isms in command line.
godefs: avoid gcc 4'isms in command line.

Fixes issue 97.

R=r
http://codereview.appspot.com/155054

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