aq_variance: make av1_log_block_wavelet_energy static

quiets -Wmissing-prototypes

Bug: aomedia:3416
Change-Id: I980f41ed18e21ec6c6a42886b4481b931f795904
diff --git a/av1/encoder/aq_variance.c b/av1/encoder/aq_variance.c
index 7e5f0f9..086928a 100644
--- a/av1/encoder/aq_variance.c
+++ b/av1/encoder/aq_variance.c
@@ -182,7 +182,7 @@
   return (unsigned int)((uint64_t)var * 256) >> num_pels_log2_lookup[bs];
 }
 
-double av1_log_block_wavelet_energy(MACROBLOCK *x, BLOCK_SIZE bs) {
+static double log_block_wavelet_energy(MACROBLOCK *x, BLOCK_SIZE bs) {
   unsigned int haar_sad = haar_ac_energy(x, bs);
   return log1p(haar_sad);
 }
@@ -193,7 +193,7 @@
   energy_midpoint = (is_stat_consumption_stage_twopass(cpi))
                         ? cpi->twopass_frame.frame_avg_haar_energy
                         : DEFAULT_E_MIDPOINT;
-  energy = av1_log_block_wavelet_energy(x, bs) - energy_midpoint;
+  energy = log_block_wavelet_energy(x, bs) - energy_midpoint;
   return clamp((int)round(energy), ENERGY_MIN, ENERGY_MAX);
 }