Replace CHECK(x && y) with two separate CHECK() calls

That way, the debug printout will tell us which of x and y that was false.

BUG=none

Review-Url: https://codereview.webrtc.org/2988153003
Cr-Commit-Position: refs/heads/master@{#19297}
diff --git a/webrtc/pc/rtpreceiver.cc b/webrtc/pc/rtpreceiver.cc
index c6a2128..99c4010 100644
--- a/webrtc/pc/rtpreceiver.cc
+++ b/webrtc/pc/rtpreceiver.cc
@@ -53,7 +53,8 @@
 }
 
 void AudioRtpReceiver::OnSetVolume(double volume) {
-  RTC_DCHECK(volume >= 0 && volume <= 10);
+  RTC_DCHECK_GE(volume, 0);
+  RTC_DCHECK_LE(volume, 10);
   cached_volume_ = volume;
   if (!channel_) {
     LOG(LS_ERROR) << "AudioRtpReceiver::OnSetVolume: No audio channel exists.";