headers_check fix: linux/random.h

fix the following 'make headers_check' warning:

  usr/include/linux/random.h:39: found __[us]{8,16,32,64} type without #include <linux/types.h>

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
diff --git a/include/linux/random.h b/include/linux/random.h
index 407ea36..25d02fe 100644
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -7,6 +7,7 @@
 #ifndef _LINUX_RANDOM_H
 #define _LINUX_RANDOM_H
 
+#include <linux/types.h>
 #include <linux/ioctl.h>
 #include <linux/irqnr.h>