wait: Remove uapi header file from main header file

There's really no overlap between uapi/linux/wait.h and linux/wait.h.
There are two files which rely on the uapi file being implcitly included,
so explicitly include it there and remove it from the main header file.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Reviewed-by: Christian Brauner <brauner@kernel.org>

include/linux/wait.h

@@ -9,7 +9,6 @@
 #include <linux/spinlock.h>
 
 #include <asm/current.h>
-#include <uapi/linux/wait.h>
 
 typedef struct wait_queue_entry wait_queue_entry_t;
 

kernel/exit.c

@@ -69,8 +69,10 @@
 #include <linux/rethook.h>
 #include <linux/sysfs.h>
 #include <linux/user_events.h>
-
 #include <linux/uaccess.h>
+
+#include <uapi/linux/wait.h>
+
 #include <asm/unistd.h>
 #include <asm/mmu_context.h>
 

kernel/pid_namespace.c

@@ -23,6 +23,7 @@
 #include <linux/sched/task.h>
 #include <linux/sched/signal.h>
 #include <linux/idr.h>
+#include <uapi/linux/wait.h>
 #include "pid_sysctl.h"
 
 static DEFINE_MUTEX(pid_caches_mutex);