iwlwifi: mvm: fix sar profile printing issue

The profile shows an invalid value because the wrong format was used.
A u8 value should use by %hhu, not %hhd.  Fix thisit by changing it to
%hhu.

Signed-off-by: Janie Tu <janiex.tu@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20201209231352.a595be52af22.I1843c3c4f9fb32fa8d439052bd0a5ad230f292e2@changeid


Signed-off-by: Luca Coelho <luciano.coelho@intel.com>