Enable init checker

clang-tidy added cppcoreguidelines-init-variables as a check, which is
something we already enforce to some extent, but getting CI to enforce
it will help reviews move faster.

Tested: Code compiles.  Noop changes.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: I7e10950de617b1d3262265572b1703f2e60b69d0
diff --git a/.clang-tidy b/.clang-tidy
index 6704aff..6f3c69d 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -201,6 +201,7 @@
 clang-analyzer-valist.ValistBase,
 clang-analyzer-webkit.NoUncountedMemberChecker,
 clang-analyzer-webkit.RefCntblBaseVirtualDtor,
+cppcoreguidelines-init-variables,
 misc-misplaced-const,
 #misc-no-recursion,
 misc-redundant-expression,