Some MT7601U adapters ship with placeholder values (0xf4) in the per-rate
power table. Feeding those bytes through s6_validate() triggers its
WARN_ON()
because bits outside the 6-bit range are set, splattering a stack trace on
every probe and needlessly tainting the kernel.

The driver already falls back to safe defaults when an EEPROM entry is
invalid, so we can simply skip per-rate values whose upper bits are set.
Mask the value locally and pass the sanitized result to s6_to_int(), keeping
later fixups working while keeping the probe path silent.

Thanks for taking a look!

Jory