Add cpufreq check warning

On some testing platform, check_freq may fail because of processor non mature (for example, turbo mode flaw). Add cpufreq check warning here for the sake of future debug at such testing platform.

Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>

diff -r 9e3d81ea61fb xen/arch/x86/acpi/cpufreq/cpufreq.c
--- a/xen/arch/x86/acpi/cpufreq/cpufreq.c	Thu Dec 18 14:14:30 2008 +0800
+++ b/xen/arch/x86/acpi/cpufreq/cpufreq.c	Thu Dec 18 14:41:09 2008 +0800
@@ -393,8 +393,10 @@ static int acpi_cpufreq_target(struct cp
 
     drv_write(&cmd);
 
-    if (!check_freqs(cmd.mask, freqs.new, data))
+    if (!check_freqs(cmd.mask, freqs.new, data)) {
+        printk(KERN_WARNING "Failed to reach the freq we set.\n");
         return -EAGAIN;
+    }
 
     for_each_cpu_mask(j, online_policy_cpus)
         cpufreq_statistic_update(j, perf->state, next_perf_state);