lisp/*.el: Fix some warnings

lisp/*.el: Fix some warnings

* lisp/battery.el (dbus-get-property):
* lisp/dired-aux.el (format-spec): Declare function.

* lisp/net/zeroconf.el (zeroconf-list-service-names)
(zeroconf-list-service-types, zeroconf-list-services):
Mark unused lexical arg.

* lisp/progmodes/hideshow.el (hs-hide-block-at-point):
* lisp/progmodes/sql.el (sql-end-of-statement):
Pass LIMIT to 'looking-back'.