Add two error codes to the Error module

One of the error codes was already reserved, this commit just makes it
explicit. The other one is a new error code for initializing return
values in the library: `MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED` should
not be returned by the library. If it is returned, then it is surely a
bug in the library or somebody is tampering with the device.
diff --git a/scripts/generate_errors.pl b/scripts/generate_errors.pl
index 2fe202e..7b66eca 100755
--- a/scripts/generate_errors.pl
+++ b/scripts/generate_errors.pl
@@ -38,7 +38,7 @@
 
 my @low_level_modules = qw( AES ARC4 ARIA ASN1 BASE64 BIGNUM BLOWFISH
                             CAMELLIA CCM CHACHA20 CHACHAPOLY CMAC CTR_DRBG DES
-                            ENTROPY GCM HKDF HMAC_DRBG MD2 MD4 MD5
+                            ENTROPY ERROR GCM HKDF HMAC_DRBG MD2 MD4 MD5
                             NET OID PADLOCK PBKDF2 PLATFORM POLY1305 RIPEMD160
                             SHA1 SHA256 SHA512 THREADING XTEA );
 my @high_level_modules = qw( CIPHER DHM ECP MD