ipv6: fix ip6_sock_set_addr_preferences() typo

ipv6: fix ip6_sock_set_addr_preferences() typo

ip6_sock_set_addr_preferences() second argument should be an integer.

SUNRPC attempts to set IPV6_PREFER_SRC_PUBLIC were
translated to IPV6_PREFER_SRC_TMP

Fixes: 18d5ad623275 ("ipv6: add ip6_sock_set_addr_preferences")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20230911154213.713941-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>