t5543: never report what we do not push

t5543: never report what we do not push

When we push some references to the git server, we expect git to report
the status of the references we are pushing; no more, no less.  But when
pusing with atomic mode, if some references cannot be pushed, Git reports
the reject message on all references in the remote repository.

Add new test cases in t5543, and fix them in latter commit.

Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>