Fix right code in the wrong place.

The recovery stuff was in the wrong if branches; the comments were
correct.
Signed-off-by: NJohn Bowler <jbowler@acm.org>

contrib/examples/pngtopng.c

@@ -59,26 +59,27 @@ int main(int argc, const char **argv)
                else
                   fprintf(stderr, "pngtopng: write %s: %s\n", argv[2],
                       image.message);
-
-               free(buffer);
             }
 
             else
-            {
                fprintf(stderr, "pngtopng: read %s: %s\n", argv[1],
                    image.message);
 
-               /* This is the only place where a 'free' is required; libpng does
-                * the cleanup on error and success, but in this case we couldn't
-                * complete the read because of running out of memory.
-                */
-               png_image_free(&image);
-            }
+            free(buffer);
          }
 
          else
+         {
             fprintf(stderr, "pngtopng: out of memory: %lu bytes\n",
                (unsigned long)PNG_IMAGE_SIZE(image));
+
+            /* This is the only place where a 'free' is required; libpng does
+             * the cleanup on error and success, but in this case we couldn't
+             * complete the read because of running out of memory and so libpng
+             * has not got to the point where it can do cleanup.
+             */
+            png_image_free(&image);
+         }
       }
 
       else