cgroup: fix a typo.

This patch fixes a typo in a comment in cgroup.c.

Signed-off-by: Rami Rosen <rami.rosen@intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 122ec55..effb636 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4037,7 +4037,7 @@
 		goto out_err;
 
 	/*
-	 * Migrate tasks one-by-one until @form is empty.  This fails iff
+	 * Migrate tasks one-by-one until @from is empty.  This fails iff
 	 * ->can_attach() fails.
 	 */
 	do {