avcodec/wmalosslessdec: fix mclms_coeffs* array size

Fixes corruption of context
Fixes: 8835659dde6a4f7dcdf341de6a45c6c8-signal_sigsegv_1dce67b_4564_cov_2504444599_classical_22_16_1_14000_v3c_0_extend_0_29.wma
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/wmalosslessdec.c

@@ -127,8 +127,8 @@ typedef struct WmallDecodeCtx {
 
     int8_t  mclms_order;
     int8_t  mclms_scaling;
-    int16_t mclms_coeffs[128];
-    int16_t mclms_coeffs_cur[4];
+    int16_t mclms_coeffs[WMALL_MAX_CHANNELS * WMALL_MAX_CHANNELS * 32];
+    int16_t mclms_coeffs_cur[WMALL_MAX_CHANNELS * WMALL_MAX_CHANNELS];
     int16_t mclms_prevvalues[WMALL_MAX_CHANNELS * 2 * 32];
     int16_t mclms_updates[WMALL_MAX_CHANNELS * 2 * 32];
     int     mclms_recent;