powerpc/pmac: Add missing unlocks in error path

In some error handling cases the lock is not unlocked.

A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
expression E1;
identifier f;
@@

f (...) { <+...
* spin_lock_irqsave (E1,...);
... when != E1
* return ...;
...+> }
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

drivers/macintosh/macio-adb.c

@@ -155,6 +155,7 @@ static int macio_adb_reset_bus(void)
 	while ((in_8(&adb->ctrl.r) & ADB_RST) != 0) {
 		if (--timeout == 0) {
 			out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) & ~ADB_RST);
+			spin_unlock_irqrestore(&macio_lock, flags);
 			return -1;
 		}
 	}

drivers/macintosh/smu.c

@@ -1183,8 +1183,10 @@ static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
 		return -EOVERFLOW;
 	spin_lock_irqsave(&pp->lock, flags);
 	if (pp->cmd.status == 1) {
-		if (file->f_flags & O_NONBLOCK)
+		if (file->f_flags & O_NONBLOCK) {
+			spin_unlock_irqrestore(&pp->lock, flags);
 			return -EAGAIN;
+		}
 		add_wait_queue(&pp->wait, &wait);
 		for (;;) {
 			set_current_state(TASK_INTERRUPTIBLE);