Clear the getlin buffer

Recent change to this bit of code didn't clear the buffer,
which causes garbage in the string if compiled with EDIT_GETLIN

win/tty/wintty.c

@@ -2046,7 +2046,7 @@ struct WinDesc *cw;
                 tty_nhbell();
                 break;
             } else {
-                char searchbuf[BUFSZ + 2], tmpbuf[BUFSZ];
+                char searchbuf[BUFSZ + 2], tmpbuf[BUFSZ] = DUMMY;
                 boolean on_curr_page = FALSE;
                 int lineno = 0;