Remove ignored xargs option in s_style

After I upgraded my distro to ubuntu2204 I started getting this warning while running s_style:

xargs: warning: options --max-args and --replace/-I/-i are mutually exclusive, ignoring previous --max-args value

This warning appears as line 36 of s_style calls xargs with invalid options:

    xargs $xp -n 1 -I{} sh ./dist/s_style {}

The n 1 is specifying -max-args 1 which then gets overrided by -I so we should remove the -n 1.