inotify: Fix fd refcount leak in inotify_add_watch().

Commit 4d97f7d5 ("inotify: Add flag IN_MASK_CREATE for
inotify_add_watch()") forgot to call fdput() before bailing out.

Fixes: 4d97f7d5

 ("inotify: Add flag IN_MASK_CREATE for inotify_add_watch()")
CC: stable@vger.kernel.org
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>