ocfs2: make several functions and variables static (and some const)

There are a variety of functions and variables that are local to the
source and do not need to be in global scope, so make them static.  Also
make a couple of char arrays static const.

Cleans up sparse warnings:
  symbol 'o2hb_heartbeat_mode_desc' was not declared. Should it be static?
  symbol 'o2hb_heartbeat_mode' was not declared. Should it be static?
  symbol 'o2hb_dependent_users' was not declared. Should it be static?
  symbol 'o2hb_region_dec_user' was not declared. Should it be static?
  symbol 'o2nm_fence_method_desc' was not declared. Should it be static?
  symbol 'lockdep_keys' was not declared. Should it be static?

Link: http://lkml.kernel.org/r/20180628131659.12133-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ocfs2/cluster/heartbeat.c

@@ -127,13 +127,13 @@ enum o2hb_heartbeat_modes {
 	O2HB_HEARTBEAT_NUM_MODES,
 };
 
-char *o2hb_heartbeat_mode_desc[O2HB_HEARTBEAT_NUM_MODES] = {
+static const char *o2hb_heartbeat_mode_desc[O2HB_HEARTBEAT_NUM_MODES] = {
 	"local",	/* O2HB_HEARTBEAT_LOCAL */
 	"global",	/* O2HB_HEARTBEAT_GLOBAL */
 };
 
 unsigned int o2hb_dead_threshold = O2HB_DEFAULT_DEAD_THRESHOLD;
-unsigned int o2hb_heartbeat_mode = O2HB_HEARTBEAT_LOCAL;
+static unsigned int o2hb_heartbeat_mode = O2HB_HEARTBEAT_LOCAL;
 
 /*
  * o2hb_dependent_users tracks the number of registered callbacks that depend
@@ -141,7 +141,7 @@ unsigned int o2hb_heartbeat_mode = O2HB_HEARTBEAT_LOCAL;
  * However only o2dlm depends on the heartbeat. It does not want the heartbeat
  * to stop while a dlm domain is still active.
  */
-unsigned int o2hb_dependent_users;
+static unsigned int o2hb_dependent_users;
 
 /*
  * In global heartbeat mode, all regions are pinned if there are one or more
@@ -2486,7 +2486,7 @@ unlock:
 	return ret;
 }
 
-void o2hb_region_dec_user(const char *region_uuid)
+static void o2hb_region_dec_user(const char *region_uuid)
 {
 	spin_lock(&o2hb_live_lock);
 

fs/ocfs2/cluster/nodemanager.c

@@ -35,7 +35,7 @@
  * cluster references throughout where nodes are looked up */
 struct o2nm_cluster *o2nm_single_cluster = NULL;
 
-char *o2nm_fence_method_desc[O2NM_FENCE_METHODS] = {
+static const char *o2nm_fence_method_desc[O2NM_FENCE_METHODS] = {
 	"reset",	/* O2NM_FENCE_RESET */
 	"panic",	/* O2NM_FENCE_PANIC */
 };

fs/ocfs2/dlmglue.c

@@ -96,7 +96,7 @@ struct ocfs2_unblock_ctl {
 };
 
 /* Lockdep class keys */
-struct lock_class_key lockdep_keys[OCFS2_NUM_LOCK_TYPES];
+static struct lock_class_key lockdep_keys[OCFS2_NUM_LOCK_TYPES];
 
 static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
 					int new_level);