pgcrypto: Remove unused error code

PXE_DEV_READ_ERROR hasn't been used since random device support was
removed from pgcrypto (fe0a0b5993).

contrib/pgcrypto/px.c

@@ -50,7 +50,6 @@ static const struct error_desc px_err_list[] = {
 	{PXE_KEY_TOO_BIG, "Key was too big"},
 	{PXE_CIPHER_INIT, "Cipher cannot be initialized ?"},
 	{PXE_HASH_UNUSABLE_FOR_HMAC, "This hash algorithm is unusable for HMAC"},
-	{PXE_DEV_READ_ERROR, "Error reading from random device"},
 	{PXE_BUG, "pgcrypto bug"},
 	{PXE_ARGUMENT_ERROR, "Illegal argument to function"},
 	{PXE_UNKNOWN_SALT_ALGO, "Unknown salt algorithm"},

contrib/pgcrypto/px.h

@@ -53,7 +53,8 @@
 #define PXE_KEY_TOO_BIG				-7
 #define PXE_CIPHER_INIT				-8
 #define PXE_HASH_UNUSABLE_FOR_HMAC	-9
-#define PXE_DEV_READ_ERROR			-10
+/* -10 is unused */
+/* -11 is unused */
 #define PXE_BUG						-12
 #define PXE_ARGUMENT_ERROR			-13
 #define PXE_UNKNOWN_SALT_ALGO		-14