decoder: Update check for first mb in slice

first_mb_in_slice shouldn't be >= mbs in the picture.

Test: poc in bugs
Bug: b/174238784
Bug: b/174507022
Bug: oss-fuzz:27856
Bug: oss-fuzz:28039
Change-Id: Id3a41c8c2ddf814910fc2d5dd4f57bdd84d28fec
(cherry picked from commit 7e06940dce7245f03fd950edf7f72ff321b2b451)
diff --git a/decoder/ih264d_parse_slice.c b/decoder/ih264d_parse_slice.c
index 927f1c0..cc1d90f 100644
--- a/decoder/ih264d_parse_slice.c
+++ b/decoder/ih264d_parse_slice.c
@@ -1100,7 +1100,7 @@
     u2_first_mb_in_slice = ih264d_uev(pu4_bitstrm_ofst,
                                      pu4_bitstrm_buf);
     if(u2_first_mb_in_slice
-                    > (ps_dec->u2_frm_ht_in_mbs * ps_dec->u2_frm_wd_in_mbs))
+                    >= (ps_dec->u2_frm_ht_in_mbs * ps_dec->u2_frm_wd_in_mbs))
     {
 
         return ERROR_CORRUPTED_SLICE;