LinuxKPI: 802.11: consistently spell TRACE-RX: as such

We have TRACE in one place and TRACE-RX in another. Spell it
"TRACE-RX: %s: ..." everywhere. Helps with pattern matching.

Sponsored by: The FreeBSD Foundation
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D45818