logd: kill(0,0) issue

- Recognize pid=0 as special case (kernel or pre-init sourced)
  and refrain from treating it in the general case.

(cherry pick from commit df5aa61f05ccbef441cf8b024d4bbc1b717451f9)

Bug: 17526159
Change-Id: I74796043ac34753c6dd10018719ebc0bcd94e012
1 file changed