wmalosslessdec: make arrays indexed by ch large enough for maximum number of channels

Fixes out of array accesses

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/wmalosslessdec.c

@@ -123,7 +123,7 @@ typedef struct WmallDecodeCtx {
     int8_t  acfilter_order;
     int8_t  acfilter_scaling;
     int64_t acfilter_coeffs[16];
-    int     acfilter_prevvalues[2][16];
+    int     acfilter_prevvalues[WMALL_MAX_CHANNELS][16];
 
     int8_t  mclms_order;
     int8_t  mclms_scaling;
@@ -145,29 +145,29 @@ typedef struct WmallDecodeCtx {
         int16_t lms_prevvalues[MAX_ORDER * 2];
         int16_t lms_updates[MAX_ORDER * 2];
         int recent;
-    } cdlms[2][9];
+    } cdlms[WMALL_MAX_CHANNELS][9];
 
-    int cdlms_ttl[2];
+    int cdlms_ttl[WMALL_MAX_CHANNELS];
 
     int bV3RTM;
 
-    int is_channel_coded[2];
-    int update_speed[2];
+    int is_channel_coded[WMALL_MAX_CHANNELS];
+    int update_speed[WMALL_MAX_CHANNELS];
 
-    int transient[2];
-    int transient_pos[2];
+    int transient[WMALL_MAX_CHANNELS];
+    int transient_pos[WMALL_MAX_CHANNELS];
     int seekable_tile;
 
-    int ave_sum[2];
+    int ave_sum[WMALL_MAX_CHANNELS];
 
-    int channel_residues[2][WMALL_BLOCK_MAX_SIZE];
+    int channel_residues[WMALL_MAX_CHANNELS][WMALL_BLOCK_MAX_SIZE];
 
-    int lpc_coefs[2][40];
+    int lpc_coefs[WMALL_MAX_CHANNELS][40];
     int lpc_order;
     int lpc_scaling;
     int lpc_intbits;
 
-    int channel_coeffs[2][WMALL_BLOCK_MAX_SIZE];
+    int channel_coeffs[WMALL_MAX_CHANNELS][WMALL_BLOCK_MAX_SIZE];
 } WmallDecodeCtx;