Include string.h to provide prototype for strcmp.

inet/tst-gethnm.c

@@ -3,6 +3,7 @@
 #include <netdb.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
 #include <unistd.h>
 #include <sys/param.h>
 #include <sys/socket.h>