avcodec/mips: Fix failed case: hevc-conformance-AMP_A_Samsung_* when enable msa

The AV_INPUT_BUFFER_PADDING_SIZE has been increased to 64, but the value is still 32
in function ff_hevc_sao_edge_filter_8_msa. So, use AV_INPUT_BUFFER_PADDING_SIZE directly.
Also, use MAX_PB_SIZE directly instead of 64. Fate tests passed.
Reviewed-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/mips/hevc_lpf_sao_msa.c

@@ -2630,7 +2630,7 @@ void ff_hevc_sao_edge_filter_8_msa(uint8_t *dst, uint8_t *src,
                                    int16_t *sao_offset_val,
                                    int eo, int width, int height)
 {
-    ptrdiff_t stride_src = (2 * 64 + 32) / sizeof(uint8_t);
+    ptrdiff_t stride_src = (2 * MAX_PB_SIZE + AV_INPUT_BUFFER_PADDING_SIZE) / sizeof(uint8_t);
 
     switch (eo) {
     case 0: