sequencer: remove unnecessary variable setting

revs.pretty_given is only ever read in builtin/log.c, and nothing from
builtin/log.c is ever called from sequencer.c.  So setting this variable
cannot do anything.  Remove it.

This was introduced in commit 62db524 ("rebase -i: generate the
script via rebase--helper", 2017-07-14), which, as per the commit
message had been adopted from calling git log, which suggests to me that
this line was copied or ported from part of builtin/log.c even though it
has no use here.

Signed-off-by: Elijah Newren <[email protected]>

Author: newren

sequencer.c

@@ -6086,7 +6086,6 @@ int sequencer_make_script(struct repository *r, struct strbuf *out, int argc,
 	revs.sort_order = REV_SORT_IN_GRAPH_ORDER;
 	revs.topo_order = 1;
 
-	revs.pretty_given = 1;
 	git_config_get_string("rebase.instructionFormat", &format);
 	if (!format || !*format) {
 		free(format);