ceph: make logical calculation functions return bool

This patch makes serverl logical caculation functions return bool to
improve readability due to these particular functions only using 0/1
as their return value.

No functional change.

Signed-off-by: Zhang Zhuoyu <zhangzhuoyu@cmss.chinamobile.com>
diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
index dcc18c6..55d2bfe 100644
--- a/net/ceph/ceph_common.c
+++ b/net/ceph/ceph_common.c
@@ -651,7 +651,7 @@
 /*
  * true if we have the mon map (and have thus joined the cluster)
  */
-static int have_mon_and_osd_map(struct ceph_client *client)
+static bool have_mon_and_osd_map(struct ceph_client *client)
 {
 	return client->monc.monmap && client->monc.monmap->epoch &&
 	       client->osdc.osdmap && client->osdc.osdmap->epoch;