nfs: Remove unneeded casts in nfs

Don't unnecessarily cast allocation return value in
fs/nfs/inode.c::nfs_alloc_inode().
Signed-off-by: Firo Yang <firogm@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/inode.c

@@ -1837,7 +1837,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 struct inode *nfs_alloc_inode(struct super_block *sb)
 {
 	struct nfs_inode *nfsi;
-	nfsi = (struct nfs_inode *)kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
+	nfsi = kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
 	if (!nfsi)
 		return NULL;
 	nfsi->flags = 0UL;