gofmt -r: match(...) arguments may be nil; add missing guards
gofmt -r: match(...) arguments may be nil; add missing guards

Fixes issue 1446.

R=rsc
CC=golang-dev
http://codereview.appspot.com/3981043

bryanxu/go-zh,rdp/rogerpack2005-golang,scirelli/scirelli-go,bryanxu/go-zh,glycerine/jeaten-go-arrayof-structof,npe9/noahevans-go9,rdp/rogerpack2005-golang,bryanxu/go-zh,glycerine/jeaten-go-arrayof-structof,sanjosh/sanjos100-tipc,d0f/go-zh,bryanxu/go-zh,glycerine/jeaten-go-arrayof-structof,glycerine/jeaten-go-arrayof-structof,scirelli/scirelli-go,mhennings/marcohennings-go,scirelli/scirelli-go,rflanagan/reginaldflanagan-project1,d0f/go-zh,npe9/noahevans-go9,scirelli/scirelli-go,npe9/noahevans-go9,rdp/rogerpack2005-golang,d0f/go-zh,Triskite/willstone-goclone,mhennings/marcohennings-go,sanjosh/sanjos100-tipc,scirelli/scirelli-go,Triskite/willstone-goclone,scirelli/scirelli-go,npe9/noahevans-go9,npe9/noahevans-go9,webfd/go-zh,mhennings/marcohennings-go,rflanagan/reginaldflanagan-project1,glycerine/jeaten-go-arrayof-structof,bryanxu/go-zh,rflanagan/reginaldflanagan-project1,scirelli/scirelli-go,bryanxu/go-zh,d0f/go-zh,webfd/go-zh,glycerine/jeaten-go-arrayof-structof,webfd/go-zh,mhennings/marcohennings-go,rdp/rogerpack2005-golang,webfd/go-zh,d0f/go-zh,sanjosh/sanjos100-tipc,mhennings/marcohennings-go,scirelli/scirelli-go,Triskite/willstone-goclone,rdp/rogerpack2005-golang,sanjosh/sanjos100-tipc,rflanagan/reginaldflanagan-project1,rflanagan/reginaldflanagan-project1,glycerine/jeaten-go-arrayof-structof,Triskite/willstone-goclone,sanjosh/sanjos100-tipc,rdp/rogerpack2005-golang,npe9/noahevans-go9,Triskite/willstone-goclone,webfd/go-zh,d0f/go-zh,d0f/go-zh,webfd/go-zh,d0f/go-zh,Triskite/willstone-goclone,sanjosh/sanjos100-tipc,mhennings/marcohennings-go,npe9/noahevans-go9,rdp/rogerpack2005-golang,rdp/rogerpack2005-golang,sanjosh/sanjos100-tipc,Triskite/willstone-goclone,Triskite/willstone-goclone,bryanxu/go-zh,sanjosh/sanjos100-tipc,webfd/go-zh,bryanxu/go-zh,mhennings/marcohennings-go,rflanagan/reginaldflanagan-project1,rflanagan/reginaldflanagan-project1,rflanagan/reginaldflanagan-project1,glycerine/jeaten-go-arrayof-structof,webfd/go-zh,npe9/noahevans-go9,mhennings/marcohennings-go