merge(s): apply consistent punctuation to "up to date" messages

Although the various "Already up to date" messages resulting from merge
attempts share identical phrasing, they use a mix of punctuation ranging
from "." to "!" and even "Yeeah!", which leads to extra work for
translators. Ease the job of translators by settling upon "." as
punctuation for all such messages.

While at it, take advantage of printf_ln() to further ease the
translation task so translators need not worry about line termination,
and fix a case of missing line termination in the (unused)
merge_ort_nonrecursive() function.

Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/merge.c

@@ -1610,7 +1610,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 			}
 		}
 		if (up_to_date) {
-			finish_up_to_date(_("Already up to date. Yeeah!"));
+			finish_up_to_date(_("Already up to date."));
 			goto done;
 		}
 	}

merge-ort-wrappers.c

@@ -30,7 +30,7 @@ int merge_ort_nonrecursive(struct merge_options *opt,
 		return -1;
 
 	if (oideq(&merge_base->object.oid, &merge->object.oid)) {
-		printf(_("Already up to date!"));
+		printf_ln(_("Already up to date."));
 		return 1;
 	}
 

merge-recursive.c

@@ -3432,7 +3432,7 @@ static int merge_trees_internal(struct merge_options *opt,
 	}
 
 	if (oideq(&merge_base->object.oid, &merge->object.oid)) {
-		output(opt, 0, _("Already up to date!"));
+		output(opt, 0, _("Already up to date."));
 		*result = head;
 		return 1;
 	}

notes-merge.c

@@ -628,7 +628,7 @@ int notes_merge(struct notes_merge_options *o,
 	if (oideq(&remote->object.oid, base_oid)) {
 		/* Already merged; result == local commit */
 		if (o->verbosity >= 2)
-			printf("Already up to date!\n");
+			printf_ln("Already up to date.");
 		oidcpy(result_oid, &local->object.oid);
 		goto found_result;
 	}