sched/headers: Prepare to move 'init_task' and 'init_thread_union' from <linux/sched.h> to <linux/sched/task.h>

Update all usage sites first.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/fs/namespace.c b/fs/namespace.c
index 131cd7b..cc1375ef 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -25,6 +25,8 @@
 #include <linux/magic.h>
 #include <linux/bootmem.h>
 #include <linux/task_work.h>
+#include <linux/sched/task.h>
+
 #include "pnode.h"
 #include "internal.h"