Revert "[clang-format] Adjust braced list detection"

It appears that this regressed the formatting of initializer lists in some
cases, see comments on https://reviews.llvm.org/D114583. I'll follow-up
by adding regression tests for these.

This reverts commit c41b3b0f.

Reviewed By: MyDeveloperDay

Differential Revision: https://reviews.llvm.org/D116000