builtin/merge.c: drop a parameter that is never used

Since the very beginning when we added the "renormalizing" parameter
to this function with 7610fa57 (merge-recursive --renormalize,
2010-08-05), nobody seems to have ever referenced it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/merge.c b/builtin/merge.c
index 41fb66d..f6894c7 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -884,7 +884,7 @@
 	return 0;
 }
 
-static int suggest_conflicts(int renormalizing)
+static int suggest_conflicts(void)
 {
 	const char *filename;
 	FILE *fp;
@@ -1557,7 +1557,7 @@
 		fprintf(stderr, _("Automatic merge went well; "
 			"stopped before committing as requested\n"));
 	else
-		ret = suggest_conflicts(option_renormalize);
+		ret = suggest_conflicts();
 
 done:
 	free(branch_to_free);