Revert prev fix for stack protector

Revert fix "Use __stack_chk_guard as the cookie on Android X86"
9c463c36 since bionic now supports
per-thread TLS entry %gs:20 for x86 stack protector

Related CL:
  https://android-review.googlesource.com/#/c/45416
  https://android-review.googlesource.com/#/c/45784

Change-Id: I49bcbe1d084aad76e1d9ffac760b1004ba233b68