Linux will report the number of page-ins so that the hypervisor can
better determine partition memory pressure.  The hardware page size
and the OS page size can be different.  In the case where the hardware
page size is 4k and the OS is running with 64k pages the code in
commit 40900194 ("powerpc: Update
page-in counter for CMM") would under-report the number of pages.

This corrects the reporting to the hypervisor by incrementing the
page_in count by 1 << PAGE_FACTOR each time.
Reported-by: NAndrew Theurer <habanero@linux.vnet.ibm.com>
Signed-off-by: NRobert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>