git-format-patch.txt: don't show -s as shorthand for multiple options

git-format-patch.txt: don't show -s as shorthand for multiple options

git-format-patch recognizes -s as shorthand only for --signoff, however,
its documentation shows -s as shorthand for both --signoff and
--no-patch. Resolve this confusion by suppressing the bogus -s shorthand
for --no-patch.

While here, also avoid showing the --no-patch option in git-format-patch
documentation since it doesn't make sense to ask to suppress the patch
while at the same time explicitly asking to format the patch (which,
after all, is the purpose of git-format-patch).

Reported-by: Kevin Brodsky <corax26@gmail.com>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>