Remove bogus vm_page_wakeup() in vm_page_cowfault() that will cause panics

in the zero-copy send path if a process attempts to write to a page
which is still in flight.

reviewed by: ken

sys/vm/vm_page.c

@@ -1791,7 +1791,6 @@ vm_page_cowfault(vm_page_t m)
 		vm_page_dirty(mnew);
 		vm_page_flag_clear(mnew, PG_BUSY);
 	}
-	vm_page_wakeup(m); /*unbusy the page */
 }
 
 void