libata: trim trailing whitespace.

Also, fixup a tabs-to-spaces block of code in ata_piix.
diff --git a/drivers/scsi/sata_qstor.c b/drivers/scsi/sata_qstor.c
index 1383e8a..dca9ed7 100644
--- a/drivers/scsi/sata_qstor.c
+++ b/drivers/scsi/sata_qstor.c
@@ -431,7 +431,7 @@
 					continue;
 				DPRINTK("ata%u: protocol %d (dev_stat 0x%X)\n",
 					ap->id, qc->tf.protocol, status);
-		
+
 				/* complete taskfile transaction */
 				pp->state = qs_state_idle;
 				ata_qc_complete(qc, status);