headers: remove sched.h from interrupt.h

After m68k's task_thread_info() doesn't refer to current,
it's possible to remove sched.h from interrupt.h and not break m68k!
Many thanks to Heiko Carstens for allowing this.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
diff --git a/net/wireless/core.c b/net/wireless/core.c
index 45b2be3..a595f71 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -14,6 +14,7 @@
 #include <linux/device.h>
 #include <linux/etherdevice.h>
 #include <linux/rtnetlink.h>
+#include <linux/sched.h>
 #include <net/genetlink.h>
 #include <net/cfg80211.h>
 #include "nl80211.h"