idct_test: drop '_t' from local typenames

_t is reserved by posix

+ switch to camelcase
  http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml#Type_Names

Change-Id: I660a77c0c58ca64075c1051ea440fdf4d7c7e6af

test/idct_test.cc

@@ -16,11 +16,11 @@
 
 #include "vpx/vpx_integer.h"
 
-typedef void (*idct_fn_t)(int16_t *input, unsigned char *pred_ptr,
-                          int pred_stride, unsigned char *dst_ptr,
-                          int dst_stride);
+typedef void (*IdctFunc)(int16_t *input, unsigned char *pred_ptr,
+                         int pred_stride, unsigned char *dst_ptr,
+                         int dst_stride);
 namespace {
-class IDCTTest : public ::testing::TestWithParam<idct_fn_t> {
+class IDCTTest : public ::testing::TestWithParam<IdctFunc> {
  protected:
   virtual void SetUp() {
     int i;
@@ -33,7 +33,7 @@ class IDCTTest : public ::testing::TestWithParam<idct_fn_t> {
 
   virtual void TearDown() { libvpx_test::ClearSystemState(); }
 
-  idct_fn_t UUT;
+  IdctFunc UUT;
   int16_t input[16];
   unsigned char output[256];
   unsigned char predict[256];