mac80211: Remove duplicate linux/slab.h include from net/mac80211/scan.c

Commit 79f460ca49d8d5700756ab7071c951311c7f29cc add a duplicate
linux/slab.h include to net/mac80211/scan.c - remove it.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/scan.c

@@ -15,7 +15,6 @@
 #include <linux/if_arp.h>
 #include <linux/rtnetlink.h>
 #include <linux/pm_qos_params.h>
-#include <linux/slab.h>
 #include <net/sch_generic.h>
 #include <linux/slab.h>
 #include <net/mac80211.h>