Disable msg_code use in fuzzing mode

bug:oss-fuzz:70102
bug:oss-fuzz:70112
Change-Id: I519c991c784bccb4bbaec622281f81015ab479a4

imageio/jpegdec.c

@@ -205,13 +205,19 @@ struct my_error_mgr {
 };
 
 static void my_error_exit(j_common_ptr dinfo) {
+  // The following code is disabled in fuzzing mode because:
+  // - the logs can be flooded due to invalid JPEG files
+  // - msg_code is wrongfully seen as uninitialized by msan when the libjpeg
+  //   dependency is not built with sanitizers enabled
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
   struct my_error_mgr* myerr = (struct my_error_mgr*)dinfo->err;
   const int msg_code = myerr->pub.msg_code;
   fprintf(stderr, "libjpeg error: ");
   dinfo->err->output_message(dinfo);
   if (msg_code == JERR_INPUT_EOF || msg_code == JERR_FILE_READ) {
     fprintf(stderr, "`jpegtran -copy all` MAY be able to process this file.\n");
   }
+#endif
   longjmp(myerr->setjmp_buffer, 1);
 }