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.

Change-Id: I2efb89a1a7faac2fcd87fd5134fafeccb6564a2d
Reviewed-on: https://go-review.googlesource.com/48862
Reviewed-by: Than McIntosh <thanm@google.com>
9 files changed