[CPUFREQ] arch/x86/kernel/cpu/cpufreq: Fix unsigned return type

In each case, the function has an unsigned return type, but returns a
negative constant to indicate an error condition.  Each function is only
called once.  For nforce2_detect_chipset, the result is only compared to 0,
and for longrun_determine_freqs, the result is stored in a variable of type
(signed) int.  Thus, for both functions, unsigned can be dropped from the
return type.

A sematic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@exists@
identifier f;
constant C;
@@

 unsigned f(...)
 { <+...
*  return -C;
 ...+> }
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Dave Jones <davej@redhat.com>

arch/x86/kernel/cpu/cpufreq/cpufreq-nforce2.c

@@ -393,7 +393,7 @@ static struct cpufreq_driver nforce2_driver = {
  * Detects nForce2 A2 and C1 stepping
  *
  */
-static unsigned int nforce2_detect_chipset(void)
+static int nforce2_detect_chipset(void)
 {
 	nforce2_dev = pci_get_subsys(PCI_VENDOR_ID_NVIDIA,
 					PCI_DEVICE_ID_NVIDIA_NFORCE2,

arch/x86/kernel/cpu/cpufreq/longrun.c

@@ -165,7 +165,7 @@ static unsigned int longrun_get(unsigned int cpu)
  * TMTA rules:
  * performance_pctg = (target_freq - low_freq)/(high_freq - low_freq)
  */
-static unsigned int __cpuinit longrun_determine_freqs(unsigned int *low_freq,
+static int __cpuinit longrun_determine_freqs(unsigned int *low_freq,
 						      unsigned int *high_freq)
 {
 	u32 msr_lo, msr_hi;