KVM: x86: degrade WARN to pr_warn_ratelimited

This warning can be triggered easily by userspace, so it should certainly not
cause a panic if panic_on_warn is set.

Reported-by: syzbot+c03f30b4f4c46bdf8575@syzkaller.appspotmail.com
Suggested-by: Alexander Potapenko <glider@google.com>
Acked-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/x86.c

@@ -1554,7 +1554,7 @@ static int set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale)
 			vcpu->arch.tsc_always_catchup = 1;
 			return 0;
 		} else {
-			WARN(1, "user requested TSC rate below hardware speed\n");
+			pr_warn_ratelimited("user requested TSC rate below hardware speed\n");
 			return -1;
 		}
 	}
@@ -1564,7 +1564,7 @@ static int set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale)
 				user_tsc_khz, tsc_khz);
 
 	if (ratio == 0 || ratio >= kvm_max_tsc_scaling_ratio) {
-		WARN_ONCE(1, "Invalid TSC scaling ratio - virtual-tsc-khz=%u\n",
+		pr_warn_ratelimited("Invalid TSC scaling ratio - virtual-tsc-khz=%u\n",
 			            user_tsc_khz);
 		return -1;
 	}