Switch to BIO_snprintf to avoid missing symbol problems on Windows

Reviewed-by: NBen Kaduk <kaduk@mit.edu>
Reviewed-by: NShane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/14063)

apps/lib/opt.c

@@ -143,7 +143,7 @@ char *opt_appname(const char *arg0)
     size_t len = strlen(prog);
 
     if (arg0 != NULL)
-        snprintf(prog + len, sizeof(prog) - len - 1, " %s", arg0);
+        BIO_snprintf(prog + len, sizeof(prog) - len - 1, " %s", arg0);
     return prog;
 }