Fix UBSan errors (left shift of negative value)

webrtc/modules/audio_coding/codecs/ilbc/hp_output.c

Index: webrtc/modules/audio_coding/codecs/ilbc/hp_output.c
diff --git a/webrtc/modules/audio_coding/codecs/ilbc/hp_output.c b/webrtc/modules/audio_coding/codecs/ilbc/hp_output.c
index bd101bf30caf0a07c17eab1a39fd8963b60a2c77..8b18c047b938cd33dc3577ce947365550fd5d159 100644
--- a/webrtc/modules/audio_coding/codecs/ilbc/hp_output.c
+++ b/webrtc/modules/audio_coding/codecs/ilbc/hp_output.c
@@ -48,7 +48,7 @@ void WebRtcIlbcfix_HpOutput(
     tmpW32 = (tmpW32>>15);
     tmpW32 += y[0] * ba[3];  /* (-a[1])*y[i-1] (high part) */
     tmpW32 += y[2] * ba[4];  /* (-a[2])*y[i-2] (high part) */
-    tmpW32 = (tmpW32<<1);
+    tmpW32 *= 2;
 
     tmpW32 += signal[i] * ba[0];  /* b[0]*x[0] */
     tmpW32 += x[0] * ba[1];  /* b[1]*x[i-1] */
@@ -77,11 +77,11 @@ void WebRtcIlbcfix_HpOutput(
     } else if (tmpW32<-268435456) {
       tmpW32 = WEBRTC_SPL_WORD32_MIN;
     } else {
-      tmpW32 <<= 3;
+      tmpW32 *= 8;
     }
 
     y[0] = (int16_t)(tmpW32 >> 16);
-    y[1] = (int16_t)((tmpW32 - (y[0] << 16)) >> 1);
+    y[1] = (int16_t)((tmpW32 & 0xffff) >> 1);
 
   }