misc: mic: Fix randconfig build error by including errno.h

This issue was reported @ https://lkml.org/lkml/2015/6/9/731

Reported-by: Jim Davis <jim.epost@gmail.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mic/scif/scif_rb.c

@@ -18,6 +18,7 @@
 #include <linux/circ_buf.h>
 #include <linux/types.h>
 #include <linux/io.h>
+#include <linux/errno.h>
 
 #include "scif_rb.h"