am: fix filename in safe_to_abort() error message

Signed-off-by: NStephan Beyer <s-beyer@gmx.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

builtin/am.c

@@ -2124,7 +2124,7 @@ static int safe_to_abort(const struct am_state *state)
 
 	if (read_state_file(&sb, state, "abort-safety", 1) > 0) {
 		if (get_oid_hex(sb.buf, &abort_safety))
-			die(_("could not parse %s"), am_path(state, "abort_safety"));
+			die(_("could not parse %s"), am_path(state, "abort-safety"));
 	} else
 		oidclr(&abort_safety);