kernel: relay: remove unnecessary NULL values from relay_open_buf

buf is assigned first, so it does not need to initialize the assignment.

Link: https://lkml.kernel.org/r/20230713234459.2908-1-kunyu@nfschina.com


Signed-off-by: Li kunyu <kunyu@nfschina.com>
Reviewed-by: Andrew Morton <akpm@linux-foudation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>