Include juggling

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/os/os-linux.h b/os/os-linux.h
index ac42264..7162dfa 100644
--- a/os/os-linux.h
+++ b/os/os-linux.h
@@ -7,6 +7,7 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <errno.h>
+#include <sched.h>
 #include <linux/unistd.h>
 #include <linux/raw.h>
 #include <linux/major.h>