don't bother with ->d_inode->i_sb - it's always equal to ->d_sb

... and neither can ever be NULL

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 912deee..889cd59 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1316,7 +1316,7 @@
 				 u32 *sid)
 {
 	int rc;
-	struct super_block *sb = dentry->d_inode->i_sb;
+	struct super_block *sb = dentry->d_sb;
 	char *buffer, *path;
 
 	buffer = (char *)__get_free_page(GFP_KERNEL);