fanotify: fanotify_init syscall declaration

This patch defines a new syscall fanotify_init() of the form:

int sys_fanotify_init(unsigned int flags, unsigned int event_f_flags,
		      unsigned int priority)

This syscall is used to create and fanotify group.  This is very similar to
the inotify_init() syscall.

Signed-off-by: Eric Paris <eparis@redhat.com>
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
new file mode 100644
index 0000000..cf176fc
--- /dev/null
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -0,0 +1,13 @@
+#include <linux/fcntl.h>
+#include <linux/fs.h>
+#include <linux/fsnotify_backend.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+
+#include "fanotify.h"
+
+SYSCALL_DEFINE3(fanotify_init, unsigned int, flags, unsigned int, event_f_flags,
+		unsigned int, priority)
+{
+	return -ENOSYS;
+}