Before this change, `-quiet` mode in clang-tidy generated meaningless
messages `xxx warnings generated` in output:
```cpp
// main.cpp
#include <iostream>
int main() {
std::cout << 42;
}
```
```console
> clang-tidy -checks='-*,readability-magic-numbers' -quiet main.cpp
82 warnings generated.
main.cpp:4:16: warning: 42 is a magic number; consider replacing it with a named constant [readability-magic-numbers]
4 | std::cout << 42;
| ^
```
As you can see, `82 warnings generated.` does not say much `quiet` mode,
this patch removes this message completely:
```console
> ./build/bin/clang-tidy -p build -checks='-*,readability-magic-numbers' -quiet main.cpp
main.cpp:4:16: warning: 42 is a magic number; consider replacing it with a named constant [readability-magic-numbers]
4 | std::cout << 42;
| ^
```
In contrast, when running without `quiet`, It gives some meaningful
information because we know how many messages were suppressed thus
calculating total messages count:
```console
> clang-tidy -checks='-*,readability-magic-numbers' main.cpp
82 warnings generated.
main.cpp:4:16: warning: 42 is a magic number; consider replacing it with a named constant [readability-magic-numbers]
4 | std::cout << 42;
| ^
Suppressed 81 warnings (81 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
```
Fixes#47042
ed26993976