test: use %ld for printing uid/gid
test: use %ld for printing uid/gid

The uid and gid fields in uv_passwd_t are of type long so use %ld for
printing them.  Fixes two -Wformat compiler warnings.

PR-URL: https://github.com/libuv/libuv/pull/797
Reviewed-By: Saúl Ibarra Corretgé <8a7991f6950ea189abf159d6ec98d2fcc13dc5f6@gmail.com>

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