re PR go/68980 (ps -o cmd in gotest isn't portable)

re PR go/68980 (ps -o cmd in gotest isn't portable)

	PR 68980
    libgo/testsuite: portable ps usage in gotest

    gotest is using "ps" to list descendant sleep
    processes in its timeout handling, grepping
    the command name.

    We are currently using the "cmd" ps output
    formatter, which is non-portable. We should
    use "comm" which is part of the POSIX
    standard, and outputs only the command name
    and not the arguments.

    Fixes https://gcc.gnu.org/PR68980

    Reviewed-on: https://go-review.googlesource.com/18426

From-SVN: r232234