NFSv4.1: Assign the right value for initval and retries for rpc timeout

Make sure the rpc timeout was assigned with the correct value for
initial timeout and max number of retries.

Fixes: 57331a59 ("NFSv4.1: Use the nfs_client's rpc timeouts for backchannel")
Signed-off-by: Samasth Norway Ananda <samasth.norway.ananda@oracle.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>