selftests: cgroup: Fixes a typo in a comment

Signed-off-by: Atul Kumar Pant <atulpant.linux@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

Author: Atul Kumar Pant

tools/testing/selftests/cgroup/test_freezer.c

@@ -740,7 +740,7 @@ static int test_cgfreezer_ptraced(const char *root)
 
 	/*
 	 * cg_check_frozen(cgroup, true) will fail here,
-	 * because the task in in the TRACEd state.
+	 * because the task is in the TRACEd state.
 	 */
 	if (cg_freeze_wait(cgroup, false))
 		goto cleanup;