libceph: split osdmap allocation and decode steps

Split osdmap allocation and initialization into a separate function,
ceph_osdmap_decode().

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 71830d7..6f64eec 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -2062,7 +2062,7 @@
 			int skipped_map = 0;
 
 			dout("taking full map %u len %d\n", epoch, maplen);
-			newmap = osdmap_decode(&p, p+maplen);
+			newmap = ceph_osdmap_decode(&p, p+maplen);
 			if (IS_ERR(newmap)) {
 				err = PTR_ERR(newmap);
 				goto bad;