ositp: fix undefined behavior from large shift

Display "2^105" instead of the expanded value.

Change-Id: I455625ab66cd86587ca35d09e1eba98ae1d87a94
Link: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=1149
Bug: 13606
Reviewed-on: https://code.wireshark.org/review/21188
Reviewed-by: Peter Wu <peter@lekensteyn.nl>
Petri-Dish: Peter Wu <peter@lekensteyn.nl>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Michael Mann <mmann78@netscape.net>

epan/dissectors/packet-ositp.c

@@ -536,19 +536,17 @@ static gboolean ositp_decode_var_part(tvbuff_t *tvb, int offset, int vp_length,
 
     case VP_RES_ERROR:
       s = tvb_get_guint8(tvb, offset);
-      proto_tree_add_uint_format(tree, hf_cotp_res_error_rate_target_value, tvb, offset, 1,
-                          s, "Residual error rate, target value: 10^%u", s);
+      proto_tree_add_uint_format_value(tree, hf_cotp_res_error_rate_target_value, tvb, offset, 1, s, "10^%u", s);
       offset += 1;
       vp_length -= 1;
 
       s = tvb_get_guint8(tvb, offset);
-      proto_tree_add_uint_format(tree, hf_cotp_res_error_rate_min_accept, tvb, offset, 1,
-                          s, "Residual error rate, minimum acceptable: 10^%u", s);
+      proto_tree_add_uint_format_value(tree, hf_cotp_res_error_rate_min_accept, tvb, offset, 1, s, "10^%u", s);
       offset += 1;
       vp_length -= 1;
 
       s = tvb_get_guint8(tvb, offset);
-      proto_tree_add_uint(tree,hf_cotp_res_error_rate_tdsu, tvb, offset, 1, 1 << s);
+      proto_tree_add_uint_format_value(tree, hf_cotp_res_error_rate_tdsu, tvb, offset, 1, s, "2^%u", s);
       offset += 1;
       vp_length -= 1;
       break;