NFS: Remove asserts from the NFS XDR code

Convert the ones that are not trivial to check into WARN_ON_ONCE().
Remove checks for things such as NFS2_MAXPATHLEN, which are trivially
done by the caller.

Add a comment to the case of nfs3_xdr_enc_setacl3args. What is being
done there is just wrong...

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
index d04f0df..06b9df4 100644
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -195,7 +195,6 @@
 {
 	__be32 *p;
 
-	BUG_ON(fh->size != NFS2_FHSIZE);
 	p = xdr_reserve_space(xdr, NFS2_FHSIZE);
 	memcpy(p, fh->data, NFS2_FHSIZE);
 }
@@ -388,7 +387,7 @@
 {
 	__be32 *p;
 
-	BUG_ON(length > NFS2_MAXNAMLEN);
+	WARN_ON_ONCE(length > NFS2_MAXNAMLEN);
 	p = xdr_reserve_space(xdr, 4 + length);
 	xdr_encode_opaque(p, name, length);
 }
@@ -428,7 +427,6 @@
 {
 	__be32 *p;
 
-	BUG_ON(length > NFS2_MAXPATHLEN);
 	p = xdr_reserve_space(xdr, 4);
 	*p = cpu_to_be32(length);
 	xdr_write_pages(xdr, pages, 0, length);