dmaengine.h: remove redundant else keyword

dmaengine_device_control returns -ENOSYS in case the dma driver doesn't have
such functionality.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

include/linux/dmaengine.h

@@ -610,7 +610,7 @@ static inline int dmaengine_device_control(struct dma_chan *chan,
 {
 	if (chan->device->device_control)
 		return chan->device->device_control(chan, cmd, arg);
-	else
+
 	return -ENOSYS;
 }