fs_truncate: provide inotify call for truncate

IN_MODIFY event should occur on file modification, which includes
truncate. This is consistent with the inotify usage on Linux.

Signed-off-by: Michal Lenc <michallenc@seznam.cz>

fs/vfs/fs_truncate.c

@@ -32,6 +32,7 @@
 
 #include <nuttx/fs/fs.h>
 
+#include "notify/notify.h"
 #include "inode/inode.h"
 
 /****************************************************************************
@@ -180,6 +181,9 @@ int ftruncate(int fd, off_t length)
   fs_putfilep(filep);
   if (ret >= 0)
     {
+#ifdef CONFIG_FS_NOTIFY
+      notify_write(filep);
+#endif
       return 0;
     }