avcodec/hevc_filter: Fix invalid shift

Fixes: runtime error: left shift of negative value -1

Fixes: 2299/clusterfuzz-testcase-minimized-4843509351710720

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit d7b3d5c3f2)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/hevc_filter.c

@@ -471,7 +471,7 @@ static int get_pcm(HEVCContext *s, int x, int y)
 
 #define TC_CALC(qp, bs)                                                 \
     tctable[av_clip((qp) + DEFAULT_INTRA_TC_OFFSET * ((bs) - 1) +       \
-                    (tc_offset >> 1 << 1),                              \
+                    (tc_offset & -2),                                   \
                     0, MAX_QP + DEFAULT_INTRA_TC_OFFSET)]
 
 static void deblocking_filter_CTB(HEVCContext *s, int x0, int y0)