ACPI: acpi_os_allocate() fixes

Replace acpi_in_resume with a more general hack
to check irqs_disabled() on any kmalloc() from ACPI.
While setting (system_state != SYSTEM_RUNNING) on resume
seemed more general, Andrew Morton preferred this approach.

http://bugzilla.kernel.org/show_bug.cgi?id=3469



Make acpi_os_allocate() into an inline function to
allow /proc/slab_allocators to work.

Delete some memset() that could fault on allocation failure.

Signed-off-by: Len Brown <len.brown@intel.com>