Add missing <string.h> include.

Change-Id: I31f5cd6fb4ff55d7cfe213f66955e3dbcbdff101
diff --git a/NetlinkManager.cpp b/NetlinkManager.cpp
index dbba303..d2e16b2 100644
--- a/NetlinkManager.cpp
+++ b/NetlinkManager.cpp
@@ -16,6 +16,7 @@
 
 #include <stdio.h>
 #include <errno.h>
+#include <string.h>
 
 #include <sys/socket.h>
 #include <sys/select.h>