fs/notify: don't show f_handle if exportfs_encode_inode_fh failed

commit 7e8824816bda16bb11ff5ff1e1212d642e57b0b3 upstream.

Currently we handle only ENOSPC.  In case of other errors the file_handle
variable isn't filled properly and we will show a part of stack.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>