Circumvent a problem of lacking GetEnvironmentVariable() in WindowsCE.

Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8596)

(cherry picked from commit 3d098890b23598d1f9455b354f46045a231459cd)

crypto/rand/randfile.c

@@ -254,7 +254,7 @@ const char *RAND_file_name(char *buf, size_t size)
     size_t len;
     int use_randfile = 1;
 
-#if defined(_WIN32) && defined(CP_UTF8)
+#if defined(_WIN32) && defined(CP_UTF8) && !defined(_WIN32_WCE)
     DWORD envlen;
     WCHAR *var;