Fix bug in ndn_memcmp: need to return the result of memcmp.
diff --git a/ndn-cpp/c/util/ndn_memory.h b/ndn-cpp/c/util/ndn_memory.h
index cd67c66..e7f6480 100644
--- a/ndn-cpp/c/util/ndn_memory.h
+++ b/ndn-cpp/c/util/ndn_memory.h
@@ -21,7 +21,7 @@
 /**
  * Use the library version of memcmp.
  */
-static inline int ndn_memcmp(unsigned char *buf1, unsigned char *buf2, unsigned int len) { memcmp(buf1, buf2, len); }
+static inline int ndn_memcmp(unsigned char *buf1, unsigned char *buf2, unsigned int len) { return memcmp(buf1, buf2, len); }
 #else
 /**
  * Use a local implementation of memcmp instead of the library version.