eng_devcrypto: close session on cleanup, not final

Close the session in digest_cleanup instead of digest_final.  A failure
in closing the session does not mean a previous successful digest final
has failed as well.
Signed-off-by: NEneas U de Queiroz <cote2004-github@yahoo.com>
Reviewed-by: NMatthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7585)

(cherry picked from commit a67203a19d379a8cc8b369587c60c46eb4e19014)

crypto/engine/eng_devcrypto.c

@@ -461,10 +461,6 @@ static int digest_final(EVP_MD_CTX *ctx, unsigned char *md)
         SYSerr(SYS_F_IOCTL, errno);
         return 0;
     }
-    if (ioctl(cfd, CIOCFSESSION, &digest_ctx->sess.ses) < 0) {
-        SYSerr(SYS_F_IOCTL, errno);
-        return 0;
-    }
 
     return 1;
 }
@@ -496,6 +492,15 @@ static int digest_copy(EVP_MD_CTX *to, const EVP_MD_CTX *from)
 
 static int digest_cleanup(EVP_MD_CTX *ctx)
 {
+    struct digest_ctx *digest_ctx =
+        (struct digest_ctx *)EVP_MD_CTX_md_data(ctx);
+
+    if (digest_ctx == NULL)
+        return 1;
+    if (ioctl(cfd, CIOCFSESSION, &digest_ctx->sess.ses) < 0) {
+        SYSerr(SYS_F_IOCTL, errno);
+        return 0;
+    }
     return 1;
 }