extmod/nimble: Make error code mapping default to MP_EIO.

Before this change, any NimBLE error that does not appear in the
ble_hs_err_to_errno_table maps to return code 0, meaning success.  If we
miss adding an error code to the table we end up returning success in case
of failure.

Instead, handle the zero case explicitly and default to MP_EIO.  This
allows removing the now-redundant MP_EIO entries from the mapping.

Author: friebel

extmod/nimble/modbluetooth_nimble.c

@@ -48,41 +48,25 @@
 
 #define ERRNO_BLUETOOTH_NOT_ACTIVE MP_ENODEV
 
+// Any BLE_HS_xxx code not in this table will default to MP_EIO.
 STATIC int8_t ble_hs_err_to_errno_table[] = {
     [BLE_HS_EAGAIN] = MP_EAGAIN,
     [BLE_HS_EALREADY] = MP_EALREADY,
     [BLE_HS_EINVAL] = MP_EINVAL,
-    [BLE_HS_EMSGSIZE] = MP_EIO,
     [BLE_HS_ENOENT] = MP_ENOENT,
     [BLE_HS_ENOMEM] = MP_ENOMEM,
     [BLE_HS_ENOTCONN] = MP_ENOTCONN,
     [BLE_HS_ENOTSUP] = MP_EOPNOTSUPP,
-    [BLE_HS_EAPP] = MP_EIO,
-    [BLE_HS_EBADDATA] = MP_EIO,
-    [BLE_HS_EOS] = MP_EIO,
-    [BLE_HS_ECONTROLLER] = MP_EIO,
     [BLE_HS_ETIMEOUT] = MP_ETIMEDOUT,
     [BLE_HS_EDONE] = MP_EIO,               // TODO: Maybe should be MP_EISCONN (connect uses this for "already connected").
     [BLE_HS_EBUSY] = MP_EBUSY,
-    [BLE_HS_EREJECT] = MP_EIO,
-    [BLE_HS_EUNKNOWN] = MP_EIO,
-    [BLE_HS_EROLE] = MP_EIO,
-    [BLE_HS_ETIMEOUT_HCI] = MP_EIO,
-    [BLE_HS_ENOMEM_EVT] = MP_EIO,
-    [BLE_HS_ENOADDR] = MP_EIO,
-    [BLE_HS_ENOTSYNCED] = MP_EIO,
-    [BLE_HS_EAUTHEN] = MP_EIO,
-    [BLE_HS_EAUTHOR] = MP_EIO,
-    [BLE_HS_EENCRYPT] = MP_EIO,
-    [BLE_HS_EENCRYPT_KEY_SZ] = MP_EIO,
-    [BLE_HS_ESTORE_CAP] = MP_EIO,
-    [BLE_HS_ESTORE_FAIL] = MP_EIO,
-    [BLE_HS_EPREEMPTED] = MP_EIO,
-    [BLE_HS_EDISABLED] = MP_EIO,
 };
 
 STATIC int ble_hs_err_to_errno(int err) {
-    if (0 <= err && err < MP_ARRAY_SIZE(ble_hs_err_to_errno_table)) {
+    if (!err) {
+        return 0;
+    }
+    if (0 <= err && err < MP_ARRAY_SIZE(ble_hs_err_to_errno_table) && ble_hs_err_to_errno_table[err]) {
         return ble_hs_err_to_errno_table[err];
     } else {
         return MP_EIO;