Fix seg-fault printing assembler statistics when the output file was not created.

PR gas/20897
	* subsegs.c (subsegs_print_statistics): Do nothing if no output
	file was created.

gas/ChangeLog

@@ -1,5 +1,9 @@
 2016-12-01  Nick Clifton  <nickc@redhat.com>
 
+	PR gas/20897
+	* subsegs.c (subsegs_print_statistics): Do nothing if no output
+	file was created.
+
 	PR gas/20895
 	* symbols.c (resolve_symbol_value): Gracefully handle erroneous
 	symbolic expressions.

gas/subsegs.c

@@ -297,6 +297,10 @@ subsegs_print_statistics (FILE *file)
   frchainS *frchp;
   asection *s;
 
+  /* PR 20897 - check to see if the output bfd was actually created.  */
+  if (stdoutput == NULL)
+    return;
+
   fprintf (file, "frag chains:\n");
   for (s = stdoutput->sections; s; s = s->next)
     {