P2P: Silence bogus compiler warnings

P2P: Silence bogus compiler warnings

It looks like the compiler version used in Android 5.0 warns about
potentially uninitialized oper_freq variable in these debug messages.
That is not really valid since this code path can be reached only if
found != 0 and in such a case, oper_freq is set. Anyway, it seems better
to avoid compiler warnings, so add an unnecessary initialization for
oper_freq for now.

Signed-off-by: Jouni Malinen <j@w1.fi>