x86/fpu: Remove 'struct task_struct' usage from __thread_fpu_end()

Migrate this function to pure 'struct fpu' usage.
Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/fpu-internal.h

@@ -344,9 +344,9 @@ static inline void __thread_set_has_fpu(struct fpu *fpu)
  * These generally need preemption protection to work,
  * do try to avoid using these on their own.
  */
-static inline void __thread_fpu_end(struct task_struct *tsk)
+static inline void __thread_fpu_end(struct fpu *fpu)
 {
-	__thread_clear_has_fpu(&tsk->thread.fpu);
+	__thread_clear_has_fpu(fpu);
 	if (!use_eager_fpu())
 		stts();
 }
@@ -372,7 +372,7 @@ static inline void drop_fpu(struct task_struct *tsk)
 		asm volatile("1: fwait\n"
 			     "2:\n"
 			     _ASM_EXTABLE(1b, 2b));
-		__thread_fpu_end(tsk);
+		__thread_fpu_end(fpu);
 	}
 
 	clear_stopped_child_used_math(tsk);

arch/x86/kernel/fpu/core.c

@@ -143,7 +143,7 @@ void fpu__save(struct task_struct *tsk)
 			__save_fpu(tsk);
 		} else {
 			fpu_save_init(fpu);
-			__thread_fpu_end(tsk);
+			__thread_fpu_end(fpu);
 		}
 	}
 	preempt_enable();