re PR libfortran/81938 (valgrind error message and heap-buffer-overflow on address sanitized libgfortran.so)

2017-10-27  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
	    Rimvydas (RJ)

	PR libgfortran/81938
	io/format.c (free_format_data): Don't try to free vlist
	descriptors past the end of the fnode array.

From-SVN: r254163