The Error ** argument must be NULL, &error_abort, &error_fatal, or a
pointer to a variable containing NULL. Passing an argument of the
latter kind twice without clearing it in between is wrong: if the
first call sets an error, it no longer points to NULL for the second
call.
check_cache_dropped() calls error_setg() in a loop. It fails to break
the loop in one instance. If a subsequent iteration error_setg()s
again, it trips error_setv()'s assertion.
Fix it to break the loop.
Fixes: 31be8a2a97ecba7d31a82932286489cac318e9e9
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200422130719.28225-3-armbru@redhat.com>