migration/multifd: Move multifd_send_setup error handling in to the function

Hide the error handling inside multifd_send_setup to make it cleaner
for the next patch to move the function around.

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240206215118.6171-4-farosas@suse.de
Signed-off-by: Peter Xu <peterx@redhat.com>
3 files changed