unix: remove unneeded SAVE_ERRNO wrappers
unix: remove unneeded SAVE_ERRNO wrappers

uv__close() won't clobber errno so there is no need to guard calls with
a SAVE_ERRNO(...) wrapper.

PR-URL: https://github.com/libuv/libuv/pull/837
Reviewed-By: Colin Ihrig <838f779c91673db29b8572ea3f54d191d3878ae2@gmail.com>

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