NFS: Convert use of __constant_htonl to htonl

In little endian cases, the macro htonl unfolds to __swab32 which
provides special case for constants. In big endian cases,
__constant_htonl and htonl expand directly to the same expression.
So, replace __constant_htonl with htonl with the goal of getting
rid of the definition of __constant_htonl completely.

The semantic patch that performs this transformation is as follows:

@@expression x;@@

- __constant_htonl(x)
+ htonl(x)
Signed-off-by: Vaishali Thakkar <vthakkar1994@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/callback_xdr.c

@@ -909,7 +909,7 @@ static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *r
 	xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
 
 	status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
-	if (status == __constant_htonl(NFS4ERR_RESOURCE))
+	if (status == htonl(NFS4ERR_RESOURCE))
 		return rpc_garbage_args;
 
 	if (hdr_arg.minorversion == 0) {