Fix msvc compile errors of inline

Use cross-platform "INLINE" macro instead of "inline"
to fix errors reported in compilers such as msvc 2013.

Change-Id: Ib92a598471f05c832c75327c4513eac43a562664
diff --git a/aom_dsp/noise_model.c b/aom_dsp/noise_model.c
index 98339f3..56f39ef 100644
--- a/aom_dsp/noise_model.c
+++ b/aom_dsp/noise_model.c
@@ -44,7 +44,7 @@
 GET_BLOCK_MEAN(uint8_t, lowbd);
 GET_BLOCK_MEAN(uint16_t, highbd);
 
-inline static double get_block_mean(const uint8_t *data, int w, int h,
+static INLINE double get_block_mean(const uint8_t *data, int w, int h,
                                     int stride, int x_o, int y_o,
                                     int block_size, int use_highbd) {
   if (use_highbd)