libbinder: fix type of return value from {send,read}_msg

send_msg and read_msg in Trusty return ssize_t instead of int.
This updates the return type in RpcTransportTipcTrusty to avoid
some UBSan failures.

Bug: 224644083
Test: atest binderRpcTest
Change-Id: Id250502a6f98ab843d48812eaa95a31a9625081f
1 file changed