Simplify WriteFile() usage under windows

include/spdlog/sinks/wincolor_sink-inl.h

@@ -151,17 +151,12 @@ void SPDLOG_INLINE wincolor_sink<ConsoleMutex>::write_to_file_(const memory_buf_
         return;
     }
 
-    DWORD total_written = 0;
-    do
-    {
     DWORD bytes_written = 0;
-        bool ok = ::WriteFile(out_handle_, formatted.data() + total_written, size - total_written, &bytes_written, nullptr) != 0;
-        if (!ok || bytes_written == 0)
+    bool ok = ::WriteFile(out_handle_, formatted.data(), size, &bytes_written, nullptr) != 0;
+    if (!ok)
     {
         throw_spdlog_ex("wincolor_sink: write_to_file_ failed. GetLastError(): " + std::to_string(::GetLastError()));
     }
-        total_written += bytes_written;
-    } while (total_written < size);
 }
 
 // wincolor_stdout_sink