ZZ Top has been forced to suspend its current tour with Jeff Beck after bassist Dusty Hill slipped and fell on his hip aboard his tour bus the evening of August 26.   The affected dates include the bills shared with Jeff Beck through September 13.  Beck will perform August 29 in Salamanca, New York, August 30 in Atlantic City, and August 31 in Mashantucket, Connecticut. The performers are asking those who hold tickets for the shows scheduled for September 6-13 to continue to do so, pending the possibility of rescheduling these concerts.