svcrdma: return 0 on success from svc_rdma_copy_inline_range

svcrdma: return 0 on success from svc_rdma_copy_inline_range

commit 94972027ab55b200e031059fd6c7a649f8248020 upstream.

The function comment specifies 0 on success and -EINVAL on invalid
parameters. Make the tail return 0 after a successful copy loop.

Fixes: d7cc73972661 ("svcrdma: support multiple Read chunks per RPC")
Cc: stable@vger.kernel.org
Signed-off-by: Joshua Rogers <linux@joshua.hu>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>