[IA64] Fix processor_get_freq

The core cpufreq code doesn't appear to understand returning -EAGAIN
for the get() function of the cpufreq_driver.  If PAL_GET_PSTATE returns
-1, such as when running on Xen, scaling_cur_freq is happy to return
4294967285 kHz (ie. (unsigned)-11).  The other drivers appear to return
0 for a failure, and doing so gives me the max frequency from
scaling_cur_frequency and "<unknown>" from cpuinfo_cur_frequency.  I
believe that's the desired behavior.
Signed-off-by: Alex Williamson <alex.williamson@hp.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/kernel/cpufreq/acpi-cpufreq.c

@@ -113,10 +113,8 @@ processor_get_freq (
 
 	saved_mask = current->cpus_allowed;
 	set_cpus_allowed(current, cpumask_of_cpu(cpu));
-	if (smp_processor_id() != cpu) {
-		ret = -EAGAIN;
+	if (smp_processor_id() != cpu)
 		goto migrate_end;
-	}
 
 	/* processor_get_pstate gets the instantaneous frequency */
 	ret = processor_get_pstate(&value);
@@ -125,7 +123,7 @@ processor_get_freq (
 		set_cpus_allowed(current, saved_mask);
 		printk(KERN_WARNING "get performance failed with error %d\n",
 		       ret);
-		ret = -EAGAIN;
+		ret = 0;
 		goto migrate_end;
 	}
 	clock_freq = extract_clock(data, value, cpu);