fix bug in $GOROOT handling: error calling Getenv.
fix bug in $GOROOT handling: error calling Getenv.

R=gri
OCL=31047
CL=31047

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