brcmfmac: Fix check for ISO3166 code

brcmfmac: Fix check for ISO3166 code

commit 9b9322db5c5a1917a66c71fe47c3848a9a31227e upstream.

The commit "regulatory: add NUL to request alpha2" increases the length of
alpha2 to 3. This causes a regression on brcmfmac, because
brcmf_cfg80211_reg_notifier() expect valid ISO3166 codes in the complete
array. So fix this accordingly.

Fixes: 657308f73e67 ("regulatory: add NUL to request alpha2")
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Acked-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
[bwh: Backported to 4.4: adjust filename]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>