cfg80211: regulatory: remove a bogus initialization

cfg80211: regulatory: remove a bogus initialization

The the __freq_reg_info() never returns NULL and the callers don't check
for NULL.  This initialization to set "reg_rule = NULL;" is just there
to make GCC happy but it's not required in current GCCs.

The problem is that Smatch sees the initialization and concludes that
this function can return NULL so it complains that the callers are not
checking for it.

Smatch used to be able to parse this correctly but we recently changed
the code from:

-       for (bw = MHZ_TO_KHZ(20); bw >= min_bw; bw = bw / 2) {
+       for (bw = MHZ_TO_KHZ(bws[i]); bw >= min_bw; bw = MHZ_TO_KHZ(bws[i--])) {

Originally Smatch used to understand that this code always iterates
through the loop once, but the change from "MHZ_TO_KHZ(20)" to
"MHZ_TO_KHZ(bws[i])" is too complicated for Smatch.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20200923084203.GC1454948@mwanda
Signed-off-by: Johannes Berg <johannes.berg@intel.com>