follow up warning fixs
cpu_id.cc(167): warning C4267: 'initializing': conversion from 'size_t' to 'int', possible loss of data
lint warning: cpu_id.cc:171:  Missing space before ( in if(  [whitespace/parens] [5]

TBR=manojkumar.bhosale@imgtec.com
BUG=libyuv:634
TEST=try bots for windows.

Review URL: https://codereview.chromium.org/2365813002 .