oprofilefs_mkdir() doesn't need superblock argument

it's always equal to ->d_sb of the second argument (parent dentry),
due to either being literally that, or ->d_sb of parent's parent.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/oprofile/oprofile_perf.c b/drivers/oprofile/oprofile_perf.c
index 52ad942..923a245 100644
--- a/drivers/oprofile/oprofile_perf.c
+++ b/drivers/oprofile/oprofile_perf.c
@@ -147,7 +147,7 @@
 		char buf[4];
 
 		snprintf(buf, sizeof buf, "%d", i);
-		dir = oprofilefs_mkdir(root->d_sb, root, buf);
+		dir = oprofilefs_mkdir(root, buf);
 		oprofilefs_create_ulong(root->d_sb, dir, "enabled", &counter_config[i].enabled);
 		oprofilefs_create_ulong(root->d_sb, dir, "event", &counter_config[i].event);
 		oprofilefs_create_ulong(root->d_sb, dir, "count", &counter_config[i].count);
diff --git a/drivers/oprofile/oprofile_stats.c b/drivers/oprofile/oprofile_stats.c
index 627dce4..8cf2fa9 100644
--- a/drivers/oprofile/oprofile_stats.c
+++ b/drivers/oprofile/oprofile_stats.c
@@ -46,14 +46,14 @@
 	char buf[10];
 	int i;
 
-	dir = oprofilefs_mkdir(root->d_sb, root, "stats");
+	dir = oprofilefs_mkdir(root, "stats");
 	if (!dir)
 		return;
 
 	for_each_possible_cpu(i) {
 		cpu_buf = &per_cpu(op_cpu_buffer, i);
 		snprintf(buf, 10, "cpu%d", i);
-		cpudir = oprofilefs_mkdir(root->d_sb, dir, buf);
+		cpudir = oprofilefs_mkdir(dir, buf);
 
 		/* Strictly speaking access to these ulongs is racy,
 		 * but we can't simply lock them, and they are
diff --git a/drivers/oprofile/oprofilefs.c b/drivers/oprofile/oprofilefs.c
index 2e2dd5c..6a34572 100644
--- a/drivers/oprofile/oprofilefs.c
+++ b/drivers/oprofile/oprofilefs.c
@@ -211,28 +211,27 @@
 }
 
 
-struct dentry *oprofilefs_mkdir(struct super_block *sb,
-	struct dentry *root, char const *name)
+struct dentry *oprofilefs_mkdir(struct dentry *parent, char const *name)
 {
 	struct dentry *dentry;
 	struct inode *inode;
 
-	mutex_lock(&root->d_inode->i_mutex);
-	dentry = d_alloc_name(root, name);
+	mutex_lock(&parent->d_inode->i_mutex);
+	dentry = d_alloc_name(parent, name);
 	if (!dentry) {
-		mutex_unlock(&root->d_inode->i_mutex);
+		mutex_unlock(&parent->d_inode->i_mutex);
 		return NULL;
 	}
-	inode = oprofilefs_get_inode(sb, S_IFDIR | 0755);
+	inode = oprofilefs_get_inode(parent->d_sb, S_IFDIR | 0755);
 	if (!inode) {
 		dput(dentry);
-		mutex_unlock(&root->d_inode->i_mutex);
+		mutex_unlock(&parent->d_inode->i_mutex);
 		return NULL;
 	}
 	inode->i_op = &simple_dir_inode_operations;
 	inode->i_fop = &simple_dir_operations;
 	d_add(dentry, inode);
-	mutex_unlock(&root->d_inode->i_mutex);
+	mutex_unlock(&parent->d_inode->i_mutex);
 	return dentry;
 }