dlm: common max length definitions

Add central definitions for max lockspace name length and max resource
name length.  The lack of central definitions has resulted in scattered
private definitions which we can now clean up, including an unused one
in dlm_device.h.

Signed-off-by: David Teigland <teigland@redhat.com>

include/linux/dlm.h

@@ -22,10 +22,6 @@
 /* Lock levels and flags are here */
 #include <linux/dlmconstants.h>
 
-
-#define DLM_RESNAME_MAXLEN	64
-
-
 typedef void dlm_lockspace_t;
 
 /*