ia64: fix format string for ia64-acpi-cpu-freq

Fix warning with %lx / s64 mismatch:

  CC [M]  drivers/cpufreq/ia64-acpi-cpufreq.o
    drivers/cpufreq/ia64-acpi-cpufreq.c: In function 'processor_get_pstate':
      warning: format '%lx' expects argument of type 'long unsigned int',
      but argument 3 has type 's64' {aka 'long long int'} [-Wformat=]
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/ia64-acpi-cpufreq.c

@@ -54,7 +54,7 @@ processor_set_pstate (
 	retval = ia64_pal_set_pstate((u64)value);
 
 	if (retval) {
-		pr_debug("Failed to set freq to 0x%x, with error 0x%lx\n",
+		pr_debug("Failed to set freq to 0x%x, with error 0x%llx\n",
 		        value, retval);
 		return -ENODEV;
 	}
@@ -77,7 +77,7 @@ processor_get_pstate (
 
 	if (retval)
 		pr_debug("Failed to get current freq with "
-			"error 0x%lx, idx 0x%x\n", retval, *value);
+			"error 0x%llx, idx 0x%x\n", retval, *value);
 
 	return (int)retval;
 }