mtd: map.h: add missing bug.h include

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

include/linux/mtd/map.h

@@ -7,6 +7,7 @@
 #include <linux/types.h>
 #include <linux/list.h>
 #include <linux/string.h>
+#include <linux/bug.h>
 
 #include <linux/mtd/compatmac.h>