Fixed some security issues

AlexeyAB

2018-06-15 e1e5abe19197f2bb56a9d320b31275db4706aa4d

 src/layer.c

@@ -11,6 +11,7 @@
#endif
      return;
   }
   if (l.mask)               free(l.mask);
   if (l.cweights)           free(l.cweights);
   if (l.indexes)            free(l.indexes);
   if (l.input_layers)       free(l.input_layers);