ARM: PL08x: fix a leak when preparing TXDs

If we fail to allocate the LLI, the prep_* function will return NULL.
However, the TXD we allocated will not be placed on any list, nor
will it be freed - we'll just drop all references to it.  Make sure
we free it rather than leaking TXDs.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

drivers/dma/amba-pl08x.c

@@ -1332,9 +1332,10 @@ static int pl08x_prep_channel_resources(struct pl08x_dma_chan *plchan,
 	int ret;
 
 	num_llis = pl08x_fill_llis_for_desc(pl08x, txd);
-
-	if (!num_llis)
+	if (!num_llis) {
+		kfree(txd);
 		return -EINVAL;
+	}
 
 	spin_lock_irqsave(&plchan->lock, plchan->lockflags);