x86/Intel: quiesce revised CPUID level message

Print this only once, for the boot CPU, unless "cpuinfo" was specified.
I found this particularly annoying on a machine which also didn't have
it MTRRs consistently set up across cores, resulting in the printing of
those messages being awfully slow (and with a second per-CPU message
added for debugging purposes this even lead to timeouts during AP
bringup).

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/arch/x86/cpu/intel.c
+++ b/xen/arch/x86/cpu/intel.c
@@ -139,7 +139,9 @@ void __devinit early_intel_workaround(st
 			misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID;
 			wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
 			c->cpuid_level = cpuid_eax(0);
-			printk("revised cpuid_level = %d\n", c->cpuid_level);
+			if (opt_cpu_info || c == &boot_cpu_data)
+				printk(KERN_INFO "revised cpuid level: %d\n",
+				       c->cpuid_level);
 		}
 	}
 }