Since irq in m48t59_private struct is defined as 'unsigned int', which will
make the following if sentence to be never true:

         if (m48t59->irq < 0)
                  m48t59->irq = NO_IRQ;

And thus it will make the m48t59_rtc_probe() is failed when the driver is
working in a no irq mode:
Signed-off-by: NMark Zhan <rongkai.zhan@windriver.com>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

[akpm@linux-foundation.org: x86_64 build fix]
[akpm@linux-foundation.org: The acpi guys changed the bin_attribute code]
Signed-off-by: NMark Zhan <rongkai.zhan@windriver.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>