[SCSI] sg: remove while (1) non-loop

The while (1) construct isn't actually a loop at all.  So let's not
pretent and obfuscate the code.
Signed-off-by: NJoern Engel <joern@logfs.org>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

drivers/scsi/sg.c

@@ -398,19 +398,15 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 			retval = -EAGAIN;
 			goto free_old_hdr;
 		}
-		while (1) {
-			retval = 0; /* following macro beats race condition */
-			__wait_event_interruptible(sfp->read_wait,
-				(sdp->detached ||
-				(srp = sg_get_rq_mark(sfp, req_pack_id))), 
-				retval);
-			if (sdp->detached) {
-				retval = -ENODEV;
-				goto free_old_hdr;
-			}
-			if (0 == retval)
-				break;
-
+		retval = 0; /* following macro beats race condition */
+		__wait_event_interruptible(sfp->read_wait,
+			(sdp->detached ||
+			(srp = sg_get_rq_mark(sfp, req_pack_id))), retval);
+		if (sdp->detached) {
+			retval = -ENODEV;
+			goto free_old_hdr;
+		}
+		if (retval) {
 			/* -ERESTARTSYS as signal hit process */
 			goto free_old_hdr;
 		}
@@ -801,25 +797,21 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 				 1, read_only, 1, &srp);
 		if (result < 0)
 			return result;
-		while (1) {
-			result = 0;	/* following macro to beat race condition */
-			__wait_event_interruptible(sfp->read_wait,
-				(srp->done || sdp->detached),
-				result);
-			if (sdp->detached)
-				return -ENODEV;
-			write_lock_irq(&sfp->rq_list_lock);
-			if (srp->done) {
-				srp->done = 2;
-				write_unlock_irq(&sfp->rq_list_lock);
-				break;
-			}
-			srp->orphan = 1;
+		result = 0;	/* following macro to beat race condition */
+		__wait_event_interruptible(sfp->read_wait,
+			(srp->done || sdp->detached), result);
+		if (sdp->detached)
+			return -ENODEV;
+		write_lock_irq(&sfp->rq_list_lock);
+		if (srp->done) {
+			srp->done = 2;
 			write_unlock_irq(&sfp->rq_list_lock);
-			return result;	/* -ERESTARTSYS because signal hit process */
+			result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
+			return (result < 0) ? result : 0;
 		}
-		result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
-		return (result < 0) ? result : 0;
+		srp->orphan = 1;
+		write_unlock_irq(&sfp->rq_list_lock);
+		return result;	/* -ERESTARTSYS because signal hit process */
 	case SG_SET_TIMEOUT:
 		result = get_user(val, ip);
 		if (result)