Do not complain when /dev/crypto does not exist.

Now the new devcrypto engine is enabled since r342009, many users started
seeing "Could not open /dev/crypto: No such file or directory".  Disable
the annoying error message as it is not very useful anyway.

Note the patch was submitted upstream.

https://github.com/openssl/openssl/pull/7896

crypto/openssl/crypto/engine/eng_devcrypto.c

@@ -24,6 +24,8 @@
 
 #include "internal/engine.h"
 
+/* #define ENGINE_DEVCRYPTO_DEBUG */
+
 #ifdef CRYPTO_ALGORITHM_MIN
 # define CHECK_BSD_STYLE_MACROS
 #endif
@@ -615,6 +617,9 @@ void engine_load_devcrypto_int()
     ENGINE *e = NULL;
 
     if ((cfd = open("/dev/crypto", O_RDWR, 0)) < 0) {
+#ifndef ENGINE_DEVCRYPTO_DEBUG
+        if (errno != ENOENT)
+#endif
         fprintf(stderr, "Could not open /dev/crypto: %s\n", strerror(errno));
         return;
     }