x86/oprofile: put SVM only code under CONFIG_HVM

The code snippet in question is to detect NMI held by SVM until STGI
is called. When Xen doesn't even support HVM guests there is no need
to check svm_stgi_label.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

xen/arch/x86/oprofile/op_model_athlon.c

@@ -319,9 +319,11 @@ static int athlon_check_ctrs(unsigned int const cpu,
 	unsigned long eip = regs->rip;
 	int mode = 0;
 	struct vcpu *v = current;
-	struct cpu_user_regs *guest_regs = guest_cpu_user_regs();
 	unsigned int const nr_ctrs = model->num_counters;
 
+#if CONFIG_HVM
+	struct cpu_user_regs *guest_regs = guest_cpu_user_regs();
+
 	if (!guest_mode(regs) &&
 	    (eip == (unsigned long)svm_stgi_label)) {
 		/* SVM guest was running when NMI occurred */
@@ -329,6 +331,7 @@ static int athlon_check_ctrs(unsigned int const cpu,
 		eip = guest_regs->rip;
 		mode = xenoprofile_get_mode(v, guest_regs);
 	} else
+#endif
 		mode = xenoprofile_get_mode(v, regs);
 
 	for (i = 0 ; i < nr_ctrs; ++i) {