avcodec/atrac3plusdsp: fix on stack alignment

Fixes fate failure on ARM
(cherry picked from commit 38f67260684aec8a02d87ab4056b1a1fbf964c03)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
diff --git a/libavcodec/atrac3plusdsp.c b/libavcodec/atrac3plusdsp.c
index 3522af1..3c68f74 100644
--- a/libavcodec/atrac3plusdsp.c
+++ b/libavcodec/atrac3plusdsp.c
@@ -599,8 +599,8 @@
                      const float *in, float *out)
 {
     int i, s, sb, t, pos_now, pos_next;
-    DECLARE_ALIGNED(32, float, idct_in)[ATRAC3P_SUBBANDS];
-    DECLARE_ALIGNED(32, float, idct_out)[ATRAC3P_SUBBANDS];
+    LOCAL_ALIGNED(32, float, idct_in, [ATRAC3P_SUBBANDS]);
+    LOCAL_ALIGNED(32, float, idct_out, [ATRAC3P_SUBBANDS]);
 
     memset(out, 0, ATRAC3P_FRAME_SAMPLES * sizeof(*out));