This is to remove noisy useless message at boot.  The message is a ton of
"ACPI Exception (acpi_memory-0492): AE_ERROR, handle is no memory device"

In my emulation, number of memory devices are not so many (only 6), but,
this messages are displayed 114 times.

It is showed by acpi_memory_register_notify_handler() which is called by
acpi_walk_namespace().

acpi_walk_namespace() parses all of ACPI's namespace and execute
acpi_memory_register_notify_handler().  So, it is called for all of the
device which is defined in namespace.  If the parsing device is not memory,
acpi_memhotplug ignores it due to "no match" and will parse next device.
This is normal route, not an exception.
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>