debuggerd: fix missed use of ptrace(PTRACE_ATTACH).

Bug: http://b/29555636
Change-Id: Ibd8a2e2b619b74aac667555b7085d6f28e367c07
(cherry picked from commit 8b6b654a5f24a481831828ff4e87fa2fe0309c1a)
(cherry picked from commit 52cf7aaa885eabc828b1d52ea52bd2cf6573cbde)
1 file changed