dmaengine: pl330: remove set but unused variable

Compiler complains (with W=1):
drivers/dma/pl330.c: In function ‘pl330_release_channel’:
drivers/dma/pl330.c:1782:21: warning:
	variable ‘pl330’ set but not used [-Wunused-but-set-variable]
  struct pl330_dmac *pl330;
                     ^~~~~

Remove the pl330 variable in pl330_release_channel as it is set but
never used.
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/pl330.c

@@ -1782,8 +1782,6 @@ static inline void _free_event(struct pl330_thread *thrd, int ev)
 
 static void pl330_release_channel(struct pl330_thread *thrd)
 {
-	struct pl330_dmac *pl330;
-
 	if (!thrd || thrd->free)
 		return;
 
@@ -1792,8 +1790,6 @@ static void pl330_release_channel(struct pl330_thread *thrd)
 	dma_pl330_rqcb(thrd->req[1 - thrd->lstenq].desc, PL330_ERR_ABORT);
 	dma_pl330_rqcb(thrd->req[thrd->lstenq].desc, PL330_ERR_ABORT);
 
-	pl330 = thrd->dmac;
-
 	_free_event(thrd, thrd->ev);
 	thrd->free = true;
 }