libceph: distinguish page array and pagelist count

Use distinct fields for tracking the number of pages in a message's
page array and in a message's page list.  Currently only one or the
other is used at a time, but that will be changing soon.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 29e4fe0..c3d8c69 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1742,7 +1742,7 @@
 	int rc = 0;
 
 	req->r_request->pages = req->r_pages;
-	req->r_request->nr_pages = req->r_num_pages;
+	req->r_request->page_count = req->r_num_pages;
 #ifdef CONFIG_BLOCK
 	req->r_request->bio = req->r_bio;
 #endif
@@ -2093,7 +2093,7 @@
 			goto out;
 		}
 		m->pages = req->r_pages;
-		m->nr_pages = req->r_num_pages;
+		m->page_count = req->r_num_pages;
 		m->page_alignment = req->r_page_alignment;
 #ifdef CONFIG_BLOCK
 		m->bio = req->r_bio;