Include poll.h, not sys/poll.h

... the posixly correct location.

src/ttynvt.c

@@ -8,6 +8,7 @@
 #include <errno.h>
 #include <fuse_opt.h>
 #include <netdb.h>
+#include <poll.h>
 #include <pthread.h>
 #include <signal.h>
 #include <stdarg.h>
@@ -22,7 +23,6 @@
 #include <linux/ppp-ioctl.h>
 #include <netinet/in.h>
 #include <sys/ioctl.h>
-#include <sys/poll.h>
 #include <sys/socket.h>
 
 #include "nvt_log.h"