esp32: Set MICROPY_USE_INTERNAL_ERRNO=0 to use toolchain's errno.h.

The underlying OS (the ESP-IDF) uses it's own internal errno codes and so
it's simpler and cleaner to use those rather than trying to convert
everything to the values defined in py/mperrno.h.

ports/esp32/mpconfigport.h

@@ -51,7 +51,7 @@
 #define MICROPY_MODULE_FROZEN_MPY           (1)
 #define MICROPY_QSTR_EXTRA_POOL             mp_qstr_frozen_const_pool
 #define MICROPY_CAN_OVERRIDE_BUILTINS       (1)
-#define MICROPY_USE_INTERNAL_ERRNO          (1)
+#define MICROPY_USE_INTERNAL_ERRNO          (0) // errno.h from xtensa-esp32-elf/sys-include/sys
 #define MICROPY_USE_INTERNAL_PRINTF         (0) // ESP32 SDK requires its own printf
 #define MICROPY_ENABLE_SCHEDULER            (1)
 #define MICROPY_SCHEDULER_DEPTH             (8)

tests/net_hosted/connect_nonblock.py

@@ -2,8 +2,9 @@
 
 try:
     import usocket as socket
+    import uerrno as errno
 except:
-    import socket
+    import socket, errno
 
 
 def test(peer_addr):
@@ -12,7 +13,7 @@ def test(peer_addr):
     try:
         s.connect(peer_addr)
     except OSError as er:
-        print(er.args[0] == 115)  # 115 is EINPROGRESS
+        print(er.args[0] == errno.EINPROGRESS)
     s.close()