mac80211: decrease IBSS creation latency

Sufficient scans (at least 2 or 3) should have been done within 7
seconds to find an existing IBSS to join.  This should improve IBSS
creation latency; and since IBSS merging is still in effect, shouldn't
have detrimental effects on eventual IBSS convergence.
Signed-off-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/mlme.c

@@ -44,7 +44,7 @@
 #define IEEE80211_RETRY_AUTH_INTERVAL (1 * HZ)
 #define IEEE80211_SCAN_INTERVAL (2 * HZ)
 #define IEEE80211_SCAN_INTERVAL_SLOW (15 * HZ)
-#define IEEE80211_IBSS_JOIN_TIMEOUT (20 * HZ)
+#define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
 
 #define IEEE80211_PROBE_DELAY (HZ / 33)
 #define IEEE80211_CHANNEL_TIME (HZ / 33)