smb: smbdirect: introduce smbdirect_socket_init()

smb: smbdirect: introduce smbdirect_socket_init()

This will make it easier to keep the initialization
in a single place.

For now it's an __always_inline function as we only
share the header files. Once move to common functions
we'll have a dedicated smbdirect.ko that exports functions...

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>