BACKPORT: mac80211_hwsim: fix check for custom world regdom array size

David Binderman reports that the conditions in the first loop
are the wrong way around - checking the array contents before
the size.

Instead of leaving the empty loop there and reordering the two
checks unify it into a single loop that skips over non-matches
and exits after the first match.

Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
(cherry picked from commit 5875755c577b00b06aba77ba471175c3e3a33c25)
[astrachan: minor rediff for context, goto vs return]
Bug: 70214720
Change-Id: I06426382cd449e36334ef3dd83af3cf6296da913
Signed-off-by: Alistair Strachan <astrachan@google.com>