[clang-format] Bug - clang-format keeps appending `\` when `ReflowComments: Never` and `ColumnLimit: 0`

With the following source
```c
#define FOO (1U) // comment
                 // comment
```

and the following config:
```yml
ColumnLimit: 0
ReflowComments: Never
```

Running clang-format once:
```c
#define FOO (1U) // comment \
                 // comment
```

Running clang-format a second time:
```c
#define FOO (1U) // comment \ \
                 // comment
```

etc