MacOS: try to fix MacOS Audio crash

Should fix #3767
(cherry picked from commit 202c4d9c4fab9bf3391c887194d4f05999634d61)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/audio_output/auhal.c

@@ -77,7 +77,7 @@
     sfm.mChannelsPerFrame, sfm.mBitsPerChannel
 
 #define FRAMESIZE 2048
-#define BUFSIZE (FRAMESIZE * 8)
+#define BUFSIZE (FRAMESIZE * 8) * 8
 #define AOUT_VAR_SPDIF_FLAG 0xf00000
 
 /*