avcodec/takdec: Use memove, avoid undefined memcpy() use

Fixes: e214333cbd94c91228e624ff39329ce6/asan_generic_4a5159_6412_96cda2530e80607210ab41ccae3d456d.tak

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 7cea3430a5)
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>

libavcodec/takdec.c

@@ -656,7 +656,7 @@ static int decorrelate(TAKDecContext *s, int c1, int c2, int length)
                 *p1++ = v;
             }
 
-            memcpy(s->residues, &s->residues[tmp], 2 * filter_order);
+            memmove(s->residues, &s->residues[tmp], 2 * filter_order);
         }
 
         emms_c();