Repo-copy: mac_is_present_np.3 -> mac_is_present.3

[Robert Watson]

Could you please repo-copy:

   src/lib/libc/posix1e/mac_is_present_np.3

to:

   src/lib/libc/posix1e/mac_is_present.3

The function was renamed, but not the file, previously.

Thanks,

Robert N M Watson