tools/metrics.py: Fix esp32 output filename due to move to CMake.

Signed-off-by: Damien George <damien@micropython.org>

tools/metrics.py

@@ -65,7 +65,7 @@ port_data = {
     "s": PortData("stm32", "stm32", "build-PYBV10/firmware.elf", "BOARD=PYBV10"),
     "c": PortData("cc3200", "cc3200", "build/WIPY/release/application.axf", "BTARGET=application"),
     "8": PortData("esp8266", "esp8266", "build-GENERIC/firmware.elf"),
-    "3": PortData("esp32", "esp32", "build-GENERIC/application.elf"),
+    "3": PortData("esp32", "esp32", "build-GENERIC/micropython.elf"),
     "r": PortData("nrf", "nrf", "build-pca10040/firmware.elf"),
     "d": PortData("samd", "samd", "build-ADAFRUIT_ITSYBITSY_M4_EXPRESS/firmware.elf"),
 }