[regression] braino in "lustre: use is_root_inode()"

In one of the places (ll_md_blocking_ast()) we had open-coded
!is_root_inode(inode) and replaced it with is_root_inode(inode).
See the last chunk of f76c23:
-                   inode != inode->i_sb->s_root->d_inode)
+                   is_root_inode(inode))
should've been
+                   !is_root_inode(inode))
obviously...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

drivers/staging/lustre/lustre/llite/namei.c

@@ -264,7 +264,7 @@ int ll_md_blocking_ast(struct ldlm_lock *lock, struct ldlm_lock_desc *desc,
 
 		if ((bits & (MDS_INODELOCK_LOOKUP | MDS_INODELOCK_PERM)) &&
 		    inode->i_sb->s_root != NULL &&
-		    is_root_inode(inode))
+		    !is_root_inode(inode))
 			ll_invalidate_aliases(inode);
 
 		iput(inode);