Fix places that trigger no-unused-lambda-capture

webrtc/modules/audio_processing/aec3/adaptive_fir_filter.cc

Index: webrtc/modules/audio_processing/aec3/adaptive_fir_filter.cc
diff --git a/webrtc/modules/audio_processing/aec3/adaptive_fir_filter.cc b/webrtc/modules/audio_processing/aec3/adaptive_fir_filter.cc
index 43cc901f006aa3aa1999a3c894898b06b34da736..09347e832447f9044c39d6ad854c9d59d157f992 100644
--- a/webrtc/modules/audio_processing/aec3/adaptive_fir_filter.cc
+++ b/webrtc/modules/audio_processing/aec3/adaptive_fir_filter.cc
@@ -507,7 +507,7 @@ void AdaptiveFirFilter::Constrain() {
   std::array<float, kFftLength> h;
   fft_.Ifft(H_[partition_to_constrain_], &h);
 
-  constexpr float kScale = 1.0f / kFftLengthBy2;
+  const float kScale = 1.0f / kFftLengthBy2;
   std::for_each(h.begin(), h.begin() + kFftLengthBy2,
                 [kScale](float& a) { a *= kScale; });
   std::fill(h.begin() + kFftLengthBy2, h.end(), 0.f);