bisect: clear flags in passed repository

69d2cfe6e8 (bisect.c: remove the_repository reference, 2018-11-10) kept
the implicit the_repository reference in clear_commit_marks_all, which
was made explicit by the previous commit (and which also renamed it to
repo_clear_commit_marks).  Replace it as well.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

bisect.c

@@ -1090,7 +1090,7 @@ enum bisect_error bisect_next_all(struct repository *r, const char *prefix)
 		  nr), nr, steps_msg);
 	free(steps_msg);
 	/* Clean up objects used, as they will be reused. */
-	repo_clear_commit_marks(the_repository, ALL_REV_FLAGS);
+	repo_clear_commit_marks(r, ALL_REV_FLAGS);
 
 	return bisect_checkout(bisect_rev, no_checkout);
 }