avcodec/hevc: Fix undefined shifts

Found-by: Clang -fsanitize=shift
Reported-by: Thierry Foucu <tfoucu@google.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/hevc.c

@@ -858,7 +858,7 @@ static void hls_sao_param(HEVCContext *s, int rx, int ry)
             } else if (sao->offset_sign[c_idx][i]) {
                 sao->offset_val[c_idx][i + 1] = -sao->offset_val[c_idx][i + 1];
             }
-            sao->offset_val[c_idx][i + 1] <<= log2_sao_offset_scale;
+            sao->offset_val[c_idx][i + 1] *= 1 << log2_sao_offset_scale;
         }
     }
 }
@@ -1300,7 +1300,7 @@ static void luma_mc_uni(HEVCContext *s, uint8_t *dst, ptrdiff_t dststride,
 
     x_off += mv->x >> 2;
     y_off += mv->y >> 2;
-    src   += y_off * srcstride + (x_off << s->sps->pixel_shift);
+    src   += y_off * srcstride + x_off * (1 << s->sps->pixel_shift);
 
     if (x_off < QPEL_EXTRA_BEFORE || y_off < QPEL_EXTRA_AFTER ||
         x_off >= pic_width - block_w - QPEL_EXTRA_AFTER ||
@@ -1455,7 +1455,7 @@ static void chroma_mc_uni(HEVCContext *s, uint8_t *dst0,
 
     x_off += mv->x >> (2 + hshift);
     y_off += mv->y >> (2 + vshift);
-    src0  += y_off * srcstride + (x_off << s->sps->pixel_shift);
+    src0  += y_off * srcstride + x_off * (1 << s->sps->pixel_shift);
 
     if (x_off < EPEL_EXTRA_BEFORE || y_off < EPEL_EXTRA_AFTER ||
         x_off >= pic_width - block_w - EPEL_EXTRA_AFTER ||