am: put spaces around pipe in usage string

This makes the style a little more consistent with other usage strings,
and will resolve a warning at
https://www.softcatala.org/recursos/quality/git.html

Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Alex Henrie 2016-09-07 22:33:08 -06:00 committed by Junio C Hamano
parent 6ebdac1bab
commit d65fdc9c5d