gdb: use function_view for iterate_over_bp_locations' callback

gdb: use function_view for iterate_over_bp_locations' callback

Use a function_view instead of function pointer + data.  Actually,
nothing uses the data anyway, but that makes iterate_over_bp_locations
more like iterate_over_breakpoints.

gdb/ChangeLog:

	* breakpoint.c (iterate_over_bp_locations): Change callback to
	function view, remove data parameter.
	* breakpoint.h (iterate_over_bp_locations): Likewise.
	* record-full.c (record_full_sync_record_breakpoints): Remove
	data parameter.

Change-Id: I66cdc94a505f67bc640bcc66865fb535ee939a57