The err_cleanup() funtion is internal so shouldn't be exported

Running a "make update" wanted to add err_cleanup to libcrypto.num which
is wrong.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

crypto/err/err.c

@@ -114,11 +114,11 @@
 #include <internal/cryptlib_int.h>
 #include <internal/threads.h>
 #include <internal/err.h>
+#include <internal/err_int.h>
 #include <openssl/lhash.h>
 #include <openssl/crypto.h>
 #include <openssl/buffer.h>
 #include <openssl/bio.h>
-#include "internal/err.h"
 #include <openssl/opensslconf.h>
 
 static void err_load_strings(int lib, ERR_STRING_DATA *str);

crypto/include/internal/err_int.h

@@ -12,5 +12,6 @@
 # define INTERNAL_ERR_INT_H
 
 void err_load_crypto_strings_int(void);
+void err_cleanup(void);
 
 #endif

include/internal/err.h

@@ -59,6 +59,5 @@
 # define INTERNAL_ERR_H
 
 void err_free_strings_int(void);
-void err_cleanup(void);
 
 #endif