aio: fix failure to put the file pointer

If the ioprio capability check fails, we return without putting
the file pointer.

Fixes: d9a08a9e61 ("fs: Add aio iopriority support")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/aio.c

@@ -1436,6 +1436,7 @@ static int aio_prep_rw(struct kiocb *req, struct iocb *iocb)
 		ret = ioprio_check_cap(iocb->aio_reqprio);
 		if (ret) {
 			pr_debug("aio ioprio check cap error: %d\n", ret);
+			fput(req->ki_filp);
 			return ret;
 		}