This function disables watchpoints:

 	Function:	IO$_LD_CONTROL

 	P1 = address of watchpt structures
 	P2 = number of watchpt structures, if 0 all entries will
 	     be removed
 	P6 = Subfunction: LDIO$K_DISABLE_WATCH

 	The watchpt structure (if specified) must contain a matching
 	lbn, action, function, flags and returncode. These can all
 	be retrieved with the LDIO$K_GET_WATCH function.

 	IOSB word 0 = status
 	     longword 1 = current number of watchpoints

 	Errors returned:

 	SS$_DATALOST	No active watchpoints
 	SS$_DATACHECK	Specified entry not found
 	SS$_NORMAL	Successful completion