rds: Fix endianness annotation for RDS_MPATH_HASH

jhash_1word accepts host endian inputs while rs_bound_port is a be16
value (sockaddr_in6.sin6_port). Use ntohs() for consistency.

Flagged by Sparse.

Signed-off-by: Ujwal Kundur <ujwal.kundur@gmail.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Link: https://patch.msgid.link/20250820175550.498-4-ujwal.kundur@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>