[PATCH] Correct bound checking from the value returned from _PPC method.

processor_perflib.c::acpi_processor_ppc_notifier() check if the value
returned by the processor's _PPC method is 0 and return failed if so.
This is wrong since 0 indicate that the bios think the processor can go
to the highest frequency.  This patch for example fix the HP NX 6125 to
allow its highest frequency to be available.

Signed-off-by: Bruno Ducrot <ducrot@poupinou.org>
Cc: "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>