terminal: always reset terminal when reading without echo

Break out of the loop to ensure restore_term() is called before
returning.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

compat/terminal.c

@@ -385,7 +385,7 @@ int read_key_without_echo(struct strbuf *buf)
 
 			ch = getchar();
 			if (ch == EOF)
-				return 0;
+				break;
 			strbuf_addch(buf, ch);
 		}
 	}