Fix ASN1_TIME_to_generalizedtime to take a const ASN1_TIME

Fixes #1526
Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3360)

crypto/asn1/a_time.c

@@ -59,7 +59,7 @@ int ASN1_TIME_check(const ASN1_TIME *t)
 }
 
 /* Convert an ASN1_TIME structure to GeneralizedTime */
-ASN1_GENERALIZEDTIME *ASN1_TIME_to_generalizedtime(ASN1_TIME *t,
+ASN1_GENERALIZEDTIME *ASN1_TIME_to_generalizedtime(const ASN1_TIME *t,
                                                    ASN1_GENERALIZEDTIME **out)
 {
     ASN1_GENERALIZEDTIME *ret = NULL;

include/openssl/asn1.h

@@ -625,8 +625,8 @@ ASN1_TIME *ASN1_TIME_set(ASN1_TIME *s, time_t t);
 ASN1_TIME *ASN1_TIME_adj(ASN1_TIME *s, time_t t,
                          int offset_day, long offset_sec);
 int ASN1_TIME_check(const ASN1_TIME *t);
-ASN1_GENERALIZEDTIME *ASN1_TIME_to_generalizedtime(ASN1_TIME *t, ASN1_GENERALIZEDTIME
-                                                   **out);
+ASN1_GENERALIZEDTIME *ASN1_TIME_to_generalizedtime(const ASN1_TIME *t,
+                                                   ASN1_GENERALIZEDTIME **out);
 int ASN1_TIME_set_string(ASN1_TIME *s, const char *str);
 
 int i2a_ASN1_INTEGER(BIO *bp, const ASN1_INTEGER *a);