re PR go/81451 (missing futex check - libgo/runtime/thread-linux.c:12:0 futex.h:13:12: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘long’)

	PR go/81451
    runtime: inline runtime_osinit
    
    We had two identical copies of runtime_osinit. They set runtime_ncpu,
    a variable that is no longer used. Removing that leaves us with two lines.
    Inline those two lines in the two places the function was called.
    
    This fixes GCC PR 81451.
    
    Reviewed-on: https://go-review.googlesource.com/48862

From-SVN: r250326