Include stdio.h for FILE in misc.h.

Fixes build on at least OpenBSD.

openbsd-compat/port-net.c

@@ -26,6 +26,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <stdarg.h>
+#include <stdio.h>
 #include <string.h>
 #include <unistd.h>
 

sshpty.c

@@ -27,6 +27,7 @@
 #endif
 #include <pwd.h>
 #include <stdarg.h>
+#include <stdio.h>
 #include <string.h>
 #include <termios.h>
 #ifdef HAVE_UTIL_H