This patch is a back port result of the following Linux commit:
 Commit: f7f71cfb
 Author: Rakib Mullick <rakib.mullick@gmail.com>
 Subject: ACPI: Fix possible recursive locking in hwregs.c

As a result of different coding style rules, the back ported code generates
source code differences between the Linux kernel and the ACPICA upstream.
This patch reduces such source code differences.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>