Using stride (# of elements) instead of pitch (bytes) in fdct8x8.

Just making fdct consistent with iht/idct/fht functions which all use
stride (# of elements) as input argument.

Change-Id: Ibc944952a192e6c7b2b6a869ec2894c01da82ed1

test/fdct8x8_test.cc

diff --git a/test/fdct8x8_test.cc b/test/fdct8x8_test.cc
index 728db6d..ffd7d23 100644
--- a/test/fdct8x8_test.cc
+++ b/test/fdct8x8_test.cc
@@ -223,7 +223,7 @@
     fwd_txfm_ = GET_PARAM(0);
     inv_txfm_ = GET_PARAM(1);
     tx_type_  = GET_PARAM(2);
-    pitch_    = 16;
+    pitch_    = 8;
     fwd_txfm_ref = fdct8x8_ref;
   }
 
@@ -234,7 +234,7 @@
     fwd_txfm_(in, out, stride);
   }
   void RunInvTxfm(int16_t *out, uint8_t *dst, int stride) {
-    inv_txfm_(out, dst, stride >> 1);
+    inv_txfm_(out, dst, stride);
   }
 
   fdct_t fwd_txfm_;