dmaengine: vdma: Fix checkpatch.pl warnings

This patch fixes the below checkpatch.pl warnings.

WARNING: void function return statements are not generally useful
+	return;
+}

WARNING: void function return statements are not generally useful
+	return;
+}

WARNING: Missing a blank line after declarations
+		u32 errors = status & XILINX_VDMA_DMASR_ALL_ERR_MASK;
+		vdma_ctrl_write(chan, XILINX_VDMA_REG_DMASR,

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: Kedareswara rao Appana <appanad@xilinx.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>