console: linenoiseProbe: check if response is valid

Previously linenoiseProbe would accept any 4 byte response, even one
that isn't expected. This adds a check that the first byte of the
response is ESC.
Suggested in https://github.com/espressif/esp-idf/issues/8839.

components/console/linenoise/linenoise.c

@@ -1057,6 +1057,10 @@ int linenoiseProbe(void) {
         if (cb < 0) {
             continue;
         }
+        if (read_bytes == 0 && c != '\x1b') {
+            /* invalid response */
+            break;
+        }
         read_bytes += cb;
     }
     /* Restore old mode */