clang-format: Fix indentation of struct definitions with array init.

Before:
  struct {
    int x;
    int y;
  } points[] = {
        {1, 2}, {2, 3},
  };

After:
  struct {
    int x;
    int y;
  } points[] = {
      {1, 2}, {2, 3},
  };

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@220195 91177308-0d34-0410-b5e6-96231b3b80d8