unix: remove superfluous parentheses in fs macros
unix: remove superfluous parentheses in fs macros

The parentheses are unnecessary because what they wrap are not macro
arguments but function arguments that aren't evaluated by the macro.

PR-URL: https://github.com/libuv/libuv/pull/479
Reviewed-By: Saúl Ibarra Corretgé <8a7991f6950ea189abf159d6ec98d2fcc13dc5f6@gmail.com>

unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso