env.bash: fix building in directory with spaces in the path.
env.bash: fix building in directory with spaces in the path.

Fixes issue 1122.
Thanks to BigBoss1964 for the solution.

R=golang-dev, r2
CC=golang-dev
http://codereview.appspot.com/2246042

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