NFS: Fix more sparse warnings

 - fs/nfs/nfs4xdr.c:2499:42: warning: incorrect type in argument 2
   (different signedness)
 - fs/nfs/nfs4xdr.c:2658:49: warning: incorrect type in argument 4
   (different explicit signedness)
 - fs/nfs/nfs4xdr.c:2683:50: warning: incorrect type in argument 4
   (different explicit signedness)
 - fs/nfs/nfs4xdr.c:3063:68: warning: incorrect type in argument 4
   (different explicit signedness)
 - fs/nfs/nfs4xdr.c:3065:68: warning: incorrect type in argument 4
   (different explicit signedness)

 - fs/nfs/callback_xdr.c:138:31: warning: incorrect type in argument 2
   (different signedness)
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/callback.h

@@ -24,7 +24,7 @@ enum nfs4_callback_opnum {
 };
 
 struct cb_compound_hdr_arg {
-	int taglen;
+	unsigned int taglen;
 	const char *tag;
 	unsigned int callback_ident;
 	unsigned nops;
@@ -32,7 +32,7 @@ struct cb_compound_hdr_arg {
 
 struct cb_compound_hdr_res {
 	__be32 *status;
-	int taglen;
+	unsigned int taglen;
 	const char *tag;
 	__be32 *nops;
 };

fs/nfs/nfs4xdr.c

@@ -2494,7 +2494,7 @@ static int decode_attr_fs_locations(struct xdr_stream *xdr, uint32_t *bitmap, st
 				int i;
 				dprintk("%s: using first %d of %d servers returned for location %d\n", __FUNCTION__, NFS4_FS_LOCATION_MAXSERVERS, m, res->nlocations);
 				for (i = loc->nservers; i < m; i++) {
-					int len;
+					unsigned int len;
 					char *data;
 					status = decode_opaque_inline(xdr, &len, &data);
 					if (unlikely(status != 0))
@@ -2642,7 +2642,7 @@ static int decode_attr_nlink(struct xdr_stream *xdr, uint32_t *bitmap, uint32_t
 	return 0;
 }
 
-static int decode_attr_owner(struct xdr_stream *xdr, uint32_t *bitmap, struct nfs_client *clp, int32_t *uid)
+static int decode_attr_owner(struct xdr_stream *xdr, uint32_t *bitmap, struct nfs_client *clp, uint32_t *uid)
 {
 	uint32_t len;
 	__be32 *p;
@@ -2667,7 +2667,7 @@ static int decode_attr_owner(struct xdr_stream *xdr, uint32_t *bitmap, struct nf
 	return 0;
 }
 
-static int decode_attr_group(struct xdr_stream *xdr, uint32_t *bitmap, struct nfs_client *clp, int32_t *gid)
+static int decode_attr_group(struct xdr_stream *xdr, uint32_t *bitmap, struct nfs_client *clp, uint32_t *gid)
 {
 	uint32_t len;
 	__be32 *p;