staging:lustre:lustre:ptlrpc: fix sparse warnings in lproc_ptlrpc.c

Fixed the below warning in sparse:

drivers/staging/lustre/lustre/ptlrpc/lproc_ptlrpc.c:184:6:
warning: symbol 'ptlrpc_lprocfs_register' was not declared.
Should it be static?
Signed-off-by: NFred Chou <fred.chou.nd@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/ptlrpc/lproc_ptlrpc.c

@@ -181,9 +181,10 @@ const char *ll_eopcode2str(__u32 opcode)
 	return ll_eopcode_table[opcode].opname;
 }
 #if defined (CONFIG_PROC_FS)
-void ptlrpc_lprocfs_register(struct proc_dir_entry *root, char *dir,
-			     char *name, struct proc_dir_entry **procroot_ret,
-			     struct lprocfs_stats **stats_ret)
+static void ptlrpc_lprocfs_register(struct proc_dir_entry *root, char *dir,
+				    char *name,
+				    struct proc_dir_entry **procroot_ret,
+				    struct lprocfs_stats **stats_ret)
 {
 	struct proc_dir_entry *svc_procroot;
 	struct lprocfs_stats *svc_stats;