lock: Add cr_wait_init helper

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

include/lock.h

@@ -11,6 +11,15 @@
 #include "syscall.h"
 #include "util.h"
 
+/*
+ * Init futex @v value
+ */
+static always_inline void cr_wait_init(u32 *v)
+{
+	u32 val = 0;
+	atomic_set(v, val);
+}
+
 /*
  * Set futex @v value to @val and wake up all waiters
  */