send-email: remove cargo-culted multi-patch pattern in tests

send-email: remove cargo-culted multi-patch pattern in tests

Change test code added in f434c083a0 ("send-email: add --no-cc,
--no-to, and --no-bcc", 2010-03-07) which blindly copied a pattern
from an earlier test added in 32ae83194b ("add a test for
git-send-email for non-threaded mails", 2009-06-12) where the
"$patches" variable was supplied more than once.

As it turns out we didn't need more than one "$patches" for the test
added in 32ae83194b either. The only tests that actually needed this
sort of invocation were the tests added in 54aae5e1a0 ("t9001:
send-email interation with --in-reply-to and --chain-reply-to",
2010-10-19).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>