It's reported in Linux community that change to utmath.c contains a style
problem:
[.../utmath.c:137]: (style) Same expression on both sides of '^='.
[.../utmath.c:174]: (style) Same expression on both sides of '^='.
This patch fixes this problem. ACPICA BZ 1422, reported by David Binderman,
fixed by Lv Zheng.