cgroup: remove CGRP_ROOT_OPTION_MASK

cgroup_root->flags only contains CGRP_ROOT_* flags and there's no
reason to mask the flags.  Remove CGRP_ROOT_OPTION_MASK.

This doesn't cause any behavior differences.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 28853e7..c4901c1 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -320,9 +320,6 @@
 
 	CGRP_ROOT_NOPREFIX	= (1 << 1), /* mounted subsystems have no named prefix */
 	CGRP_ROOT_XATTR		= (1 << 2), /* supports extended attributes */
-
-	/* mount options live below bit 16 */
-	CGRP_ROOT_OPTION_MASK	= (1 << 16) - 1,
 };
 
 /*
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index cd02e99..5411fff 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1490,11 +1490,10 @@
 	removed_mask = root->subsys_mask & ~opts.subsys_mask;
 
 	/* Don't allow flags or name to change at remount */
-	if (((opts.flags ^ root->flags) & CGRP_ROOT_OPTION_MASK) ||
+	if ((opts.flags ^ root->flags) ||
 	    (opts.name && strcmp(opts.name, root->name))) {
 		pr_err("option or name mismatch, new: 0x%x \"%s\", old: 0x%x \"%s\"\n",
-		       opts.flags & CGRP_ROOT_OPTION_MASK, opts.name ?: "",
-		       root->flags & CGRP_ROOT_OPTION_MASK, root->name);
+		       opts.flags, opts.name ?: "", root->flags, root->name);
 		ret = -EINVAL;
 		goto out_unlock;
 	}
@@ -1762,7 +1761,7 @@
 			goto out_unlock;
 		}
 
-		if ((root->flags ^ opts.flags) & CGRP_ROOT_OPTION_MASK) {
+		if (root->flags ^ opts.flags) {
 			if ((root->flags | opts.flags) & CGRP_ROOT_SANE_BEHAVIOR) {
 				pr_err("sane_behavior: new mount options should match the existing superblock\n");
 				ret = -EINVAL;