isdn: make capidrv module parameter "debugmode" writeable

Being able to change the debugmode module parameter of capidrv on the
fly is quite useful for debugging and doesn't do any harm.
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/isdn/capi/capidrv.c

@@ -40,7 +40,7 @@ static int debugmode = 0;
 MODULE_DESCRIPTION("CAPI4Linux: Interface to ISDN4Linux");
 MODULE_AUTHOR("Carsten Paeth");
 MODULE_LICENSE("GPL");
-module_param(debugmode, uint, 0);
+module_param(debugmode, uint, S_IRUGO|S_IWUSR);
 
 /* -------- type definitions ----------------------------------------- */