print.c: add length check to loop

Note that it was impossible to actually overflow
the buffer, and there is a check to flush and restart
if it gets to within a few bytes of the end, but static
analyzers (CID: 1477927) are unlikely to be able to work
this out.

epan/print.c

@@ -1812,7 +1812,7 @@ print_escaped_xml(FILE *fh, const char *unescaped_string)
         return;
     }
 
-    for (p = unescaped_string; *p != '\0'; p++) {
+    for (p = unescaped_string; *p != '\0' && (offset<(ESCAPED_BUFFER_MAX-1)); p++) {
         switch (*p) {
         case '&':
             (void) g_strlcpy(&temp_buffer[offset], "&amp;", ESCAPED_BUFFER_MAX-offset);