std.os.linux: do not use `usingnamespace` to define getauxval
This usage of `usingnamespace` was removed fairly trivially - the
resulting code is, IMO, more clear.
Eliminates one more usage of `usingnamespace` from the standard library.
229800482dmlugg committed on 3/8/2024, 8:02:44 AMparent14ab9fb