do_each_thread/while_each_thread wrap a block of code that is in this format:

	for (...)
		do
			...
		while

If curly braces do not surround the inner loop the following warning is
generated by sparse:

	warning: do-while statement is not a compound statement

Fix the warning by adding the braces.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

kernel/sys.c

@@ -190,10 +190,10 @@ SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
 				 !(user = find_user(who)))
 				goto out_unlock;	/* No processes for this user */
 
-			do_each_thread(g, p)
+			do_each_thread(g, p) {
 				if (__task_cred(p)->uid == who)
 					error = set_one_prio(p, niceval, error);
-			while_each_thread(g, p);
+			} while_each_thread(g, p);
 			if (who != cred->uid)
 				free_uid(user);		/* For find_user() */
 			break;
@@ -253,13 +253,13 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who)
 				 !(user = find_user(who)))
 				goto out_unlock;	/* No processes for this user */
 
-			do_each_thread(g, p)
+			do_each_thread(g, p) {
 				if (__task_cred(p)->uid == who) {
 					niceval = 20 - task_nice(p);
 					if (niceval > retval)
 						retval = niceval;
 				}
-			while_each_thread(g, p);
+			} while_each_thread(g, p);
 			if (who != cred->uid)
 				free_uid(user);		/* for find_user() */
 			break;