sysycall: remove creds_linux_test.go It is unprecedented to add tests to package syscall, especially system-specific ones. Not a policy worth changing right before Go 1 is cut.
sysycall: remove creds_linux_test.go
It is unprecedented to add tests to package syscall, especially
system-specific ones. Not a policy worth changing right before Go 1
is cut.

The sole existing test, passfd_test.go, contains the line
        // +build linux darwin probablyfreebsd probablyopenbsd
which argues that this is not a subject to be undertaking likely.
Note that passfd_test.go also went in just now. It's the only test
in syscall.

Deleting for now, will reconsider after Go 1.

R=golang-dev, bradfitz, r, dsymonds
CC=golang-dev
http://codereview.appspot.com/5846063

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