sched/headers: Move CONFIG_TASK_XACCT bits from <linux/sched.h> to <linux/sched/xacct.h>

The CONFIG_TASK_XACCT=y accounting inline functions are only used by
fs/read_write.c, so move them into their separate header.
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>

include/linux/sched.h

@@ -2104,44 +2104,6 @@ extern struct task_group root_task_group;
 extern int task_can_switch_user(struct user_struct *up,
 					struct task_struct *tsk);
 
-#ifdef CONFIG_TASK_XACCT
-static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
-{
-	tsk->ioac.rchar += amt;
-}
-
-static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
-{
-	tsk->ioac.wchar += amt;
-}
-
-static inline void inc_syscr(struct task_struct *tsk)
-{
-	tsk->ioac.syscr++;
-}
-
-static inline void inc_syscw(struct task_struct *tsk)
-{
-	tsk->ioac.syscw++;
-}
-#else
-static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
-{
-}
-
-static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
-{
-}
-
-static inline void inc_syscr(struct task_struct *tsk)
-{
-}
-
-static inline void inc_syscw(struct task_struct *tsk)
-{
-}
-#endif
-
 #ifndef TASK_SIZE_OF
 #define TASK_SIZE_OF(tsk)	TASK_SIZE
 #endif

include/linux/sched/xacct.h

 #ifndef _LINUX_SCHED_XACCT_H
 #define _LINUX_SCHED_XACCT_H
 
+/*
+ * Extended task accounting methods:
+ */
+
 #include <linux/sched.h>
 
+#ifdef CONFIG_TASK_XACCT
+static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
+{
+	tsk->ioac.rchar += amt;
+}
+
+static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
+{
+	tsk->ioac.wchar += amt;
+}
+
+static inline void inc_syscr(struct task_struct *tsk)
+{
+	tsk->ioac.syscr++;
+}
+
+static inline void inc_syscw(struct task_struct *tsk)
+{
+	tsk->ioac.syscw++;
+}
+#else
+static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
+{
+}
+
+static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
+{
+}
+
+static inline void inc_syscr(struct task_struct *tsk)
+{
+}
+
+static inline void inc_syscw(struct task_struct *tsk)
+{
+}
+#endif
+
 #endif /* _LINUX_SCHED_XACCT_H */