mac80211: fix virtual monitor interface addition

mac80211: fix virtual monitor interface addition

Since the commit below, cfg80211_chandef_dfs_required()
will warn if it gets a an NL80211_IFTYPE_UNSPECIFIED iftype
as explicitely written in the commit log.
When an virtual monitor interface is added, its type is set
in ieee80211_sub_if_data.vif.type, but not in
ieee80211_sub_if_data.wdev.iftype which is passed to
cfg80211_chandef_dfs_required() hence resulting in the
following warning:

WARNING: CPU: 1 PID: 21265 at net/wireless/chan.c:376 cfg80211_chandef_dfs_required+0xbc/0x130 [cfg80211]()
Modules linked in: [...]
CPU: 1 PID: 21265 Comm: ifconfig Tainted: G        W  O 3.13.11+ #12
Hardware name: Dell Inc. Latitude E6410/0667CC, BIOS A01 03/05/2010
 0000000000000009 ffff88008f5fdb08 ffffffff817d4219 ffff88008f5fdb50
 ffff88008f5fdb40 ffffffff8106f57d 0000000000000000 0000000000000000
 ffff880081062fb8 ffff8800810604e0 0000000000000001 ffff88008f5fdba0
Call Trace:
 [<ffffffff817d4219>] dump_stack+0x4d/0x66
 [<ffffffff8106f57d>] warn_slowpath_common+0x7d/0xa0
 [<ffffffff8106f5ec>] warn_slowpath_fmt+0x4c/0x50
 [<ffffffffa04ea4ec>] cfg80211_chandef_dfs_required+0xbc/0x130 [cfg80211]
 [<ffffffffa06b1024>] ieee80211_vif_use_channel+0x94/0x500 [mac80211]
 [<ffffffffa0684e6b>] ieee80211_add_virtual_monitor+0x1ab/0x5c0 [mac80211]
 [<ffffffffa0686ae5>] ieee80211_do_open+0xe75/0x1580 [mac80211]
 [<ffffffffa0687259>] ieee80211_open+0x69/0x70 [mac80211]
[snip]

Fixes: 00ec75fc5a64 ("cfg80211: pass the actual iftype when calling cfg80211_chandef_dfs_required()")
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Acked-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>