NFS: Fix sparse warnings

Fix the following sparse warnings:

fs/nfs/direct.c:221:6: warning: symbol 'nfs_direct_readpage_release' was
not declared. Should it be static?
fs/nfs/read.c:38:43: warning: non-ANSI function declaration of function
'nfs_readhdr_alloc'
fs/nfs/objlayout/objio_osd.c:214:5: warning: symbol '__alloc_objio_seg'
was not declared. Should it be static?

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Fred Isaman <iisaman@netapp.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index dca9c81..257d009 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -218,7 +218,7 @@
 	nfs_direct_req_release(dreq);
 }
 
-void nfs_direct_readpage_release(struct nfs_page *req)
+static void nfs_direct_readpage_release(struct nfs_page *req)
 {
 	dprintk("NFS: direct read done (%s/%lld %d@%lld)\n",
 		req->wb_context->dentry->d_inode->i_sb->s_id,
diff --git a/fs/nfs/objlayout/objio_osd.c b/fs/nfs/objlayout/objio_osd.c
index fbf4874..b47277ba 100644
--- a/fs/nfs/objlayout/objio_osd.c
+++ b/fs/nfs/objlayout/objio_osd.c
@@ -211,7 +211,7 @@
 	memcpy(ocomp->cred, src_comp->oc_cap.cred, sizeof(ocomp->cred));
 }
 
-int __alloc_objio_seg(unsigned numdevs, gfp_t gfp_flags,
+static int __alloc_objio_seg(unsigned numdevs, gfp_t gfp_flags,
 		       struct objio_segment **pseg)
 {
 /*	This is the in memory structure of the objio_segment
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 37c9eb2..f23cf25 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -35,7 +35,7 @@
 
 static struct kmem_cache *nfs_rdata_cachep;
 
-struct nfs_read_header *nfs_readhdr_alloc()
+struct nfs_read_header *nfs_readhdr_alloc(void)
 {
 	struct nfs_read_header *rhdr;