lbutils: don't set USE_OPENAT and USE_URANDOM

these can be set explicitly in the compiler flags,
e.g.

make CC="cc -DUSE_OPENAT=1 -DUSE_URANDOM=1"

these options, if set to 1, will cause you to use
the code as if it were running on non-linux systems
such as openbsd. of course, some differences will
still exist, but this is useful for portability
testing when compiling on linux.

Signed-off-by: Leah Rowe <leah@libreboot.org>

util/libreboot-utils/lib/rand.c

@@ -154,7 +154,7 @@ retry_rand: {
 
 	while (rw_retry(saved_errno,
 		rc = read_on_eintr(fd,
-		    (unsigned char *)buf + off, n - off, 0)));
+		    (unsigned char *)buf + off, n - off)));
 #elif defined(__linux__)
 	long rc;
 	while (sys_retry(saved_errno,
@@ -183,10 +183,6 @@ retry_rand: {
 	reset_caller_errno(0);
 	return;
 err:
-#if defined(USE_URANDOM) && \
-    ((USE_URANDOM) > 0)
-	close_on_eintr(&fd);
-#endif
 	(void) with_fallback_errno(ECANCELED);
 	exitf("Randomisierungsfehler");
 	exit(EXIT_FAILURE);