Remove unreachable returns after longjmp Bug: aomedia:444707595 Change-Id: I406cdc27ec20b0317b341dce40cc70106e600605

diff --git a/av1/decoder/obu.c b/av1/decoder/obu.c
index c58f6b2..5233fba 100644
--- a/av1/decoder/obu.c
+++ b/av1/decoder/obu.c

@@ -293,7 +293,7 @@
 }
 
 // On success, returns the tile group header size. On failure, calls
-// aom_internal_error() and returns -1.
+// aom_internal_error() and does not return.
 static int32_t read_tile_group_header(AV1Decoder *pbi,
                                       struct aom_read_bit_buffer *rb,
                                       int *start_tile, int *end_tile,
@@ -310,7 +310,6 @@
       aom_internal_error(
           &pbi->error, AOM_CODEC_UNSUP_BITSTREAM,
           "For OBU_FRAME type obu tile_start_and_end_present_flag must be 0");
-      return -1;
     }
   }
   if (tiles->large_scale || num_tiles == 1 ||
@@ -326,20 +325,17 @@
     aom_internal_error(&pbi->error, AOM_CODEC_CORRUPT_FRAME,
                        "tg_start (%d) must be equal to %d", *start_tile,
                        pbi->next_start_tile);
-    return -1;
   }
   if (*start_tile > *end_tile) {
     aom_internal_error(
         &pbi->error, AOM_CODEC_CORRUPT_FRAME,
         "tg_end (%d) must be greater than or equal to tg_start (%d)", *end_tile,
         *start_tile);
-    return -1;
   }
   if (*end_tile >= num_tiles) {
     aom_internal_error(&pbi->error, AOM_CODEC_CORRUPT_FRAME,
                        "tg_end (%d) must be less than NumTiles (%d)", *end_tile,
                        num_tiles);
-    return -1;
   }
   pbi->next_start_tile = (*end_tile == num_tiles - 1) ? 0 : *end_tile + 1;
 
@@ -887,6 +883,9 @@
   const uint8_t *frame_header = data;
   uint32_t frame_header_size = 0;
   ObuHeader obu_header;
+
+  assert(pbi->error.setjmp);
+
   memset(&obu_header, 0, sizeof(obu_header));
   pbi->seen_frame_header = 0;
   pbi->next_start_tile = 0;