vpx_ve_predictor_4x4_c: quiet unused param warning

Change-Id: I62234260e2d2de94d602c6d8095c8f8124334052

vpx_dsp/intrapred.c

@@ -326,6 +326,7 @@ void vpx_ve_predictor_4x4_c(uint8_t *dst, ptrdiff_t stride,
   const int K = above[2];
   const int L = above[3];
   const int M = above[4];
+  (void)left;
 
   dst[0] = AVG3(H, I, J);
   dst[1] = AVG3(I, J, K);