MS-MMS: Use format_text_string()

The length of a string transcoded from UTF-16 to UTF-8 can be
shorter (or longer) than the original length in bytes in the packet.
Use the new string length, not the original length.

Use format_text_string, which is a convenience function that
calls strlen.

Fix #19086

epan/dissectors/packet-ms-mms.c

@@ -740,7 +740,7 @@ static void dissect_client_transport_info(tvbuff_t *tvb, packet_info *pinfo, pro
                                  transport_info, "Transport: (%s)", transport_info);
 
     col_append_fstr(pinfo->cinfo, COL_INFO, " (%s)",
-                    format_text(pinfo->pool, (guchar*)transport_info, length_remaining - 20));
+                    format_text_string(pinfo->pool, (const guchar*)transport_info));
 
 
     /* Try to extract details from this string */
@@ -837,7 +837,7 @@ static void dissect_server_info(tvbuff_t *tvb, packet_info *pinfo, proto_tree *t
                             ENC_UTF_16|ENC_LITTLE_ENDIAN, pinfo->pool, &server_version);
 
         col_append_fstr(pinfo->cinfo, COL_INFO, " (version='%s')",
-                    format_text(pinfo->pool, (const guchar*)server_version, strlen(server_version)));
+                    format_text_string(pinfo->pool, (const guchar*)server_version));
     }
     offset += (server_version_length*2);
 
@@ -891,7 +891,7 @@ static void dissect_client_player_info(tvbuff_t *tvb, packet_info *pinfo, proto_
                         ENC_UTF_16|ENC_LITTLE_ENDIAN, pinfo->pool, &player_info);
 
     col_append_fstr(pinfo->cinfo, COL_INFO, " (%s)",
-                    format_text(pinfo->pool, (const guchar*)player_info, strlen(player_info)));
+                    format_text_string(pinfo->pool, (const guchar*)player_info));
 }
 
 /* Dissect info about where client wants to start playing from */
@@ -966,7 +966,7 @@ static void dissect_request_server_file(tvbuff_t *tvb, packet_info *pinfo, proto
                         ENC_UTF_16|ENC_LITTLE_ENDIAN, pinfo->pool, &server_file);
 
     col_append_fstr(pinfo->cinfo, COL_INFO, " (%s)",
-                    format_text(pinfo->pool, (const guchar*)server_file, strlen(server_file)));
+                    format_text_string(pinfo->pool, (const guchar*)server_file));
 }
 
 /* Dissect media details from server */