kmsan: Set -fno-sanitize-memory-param-retval for now

As of LLVM 16, -fsanitize-memory-param-retval is the default. It yields
significantly smaller code, but the KMSAN runtime interceptors need to
be updated to stop checking shadow state of parameters. Apply a minimal
workaround for now.

MFC after: 3 days
Sponsored by: Klara, Inc.
Sponsored by: Juniper Networks, Inc.