x86/fpu: Rename restore_fpu_checking() to copy_fpstate_to_fpregs()

fpu_restore_checking() is a helper function of restore_fpu_checking(),
but this is not apparent from the naming.

Both copy fpstate contents to fpregs, while the fuller variant does
a full copy without leaking information.

So rename them to:

    copy_fpstate_to_fpregs()
  __copy_fpstate_to_fpregs()

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
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/kvm/x86.c

@@ -7030,7 +7030,7 @@ void kvm_load_guest_fpu(struct kvm_vcpu *vcpu)
 	kvm_put_guest_xcr0(vcpu);
 	vcpu->guest_fpu_loaded = 1;
 	__kernel_fpu_begin();
-	fpu_restore_checking(&vcpu->arch.guest_fpu);
+	__copy_fpstate_to_fpregs(&vcpu->arch.guest_fpu);
 	trace_kvm_fpu(1);
 }