x86/fpu: Use 'struct fpu' in fpstate_alloc_init()

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/math-emu/fpu_entry.c

@@ -150,7 +150,7 @@ void math_emulate(struct math_emu_info *info)
 	struct fpu *fpu = &current->thread.fpu;
 
 	if (!fpu->fpstate_active) {
-		if (fpstate_alloc_init(current)) {
+		if (fpstate_alloc_init(fpu)) {
 			do_group_exit(SIGKILL);
 			return;
 		}