make b_print.c consistent with the rest of OpenSSL:
disable assert() except for debug builds

crypto/bio/bss_bio.c

diff --git a/crypto/bio/bss_bio.c b/crypto/bio/bss_bio.c
index a5da473..1c485a4 100644
--- a/crypto/bio/bss_bio.c
+++ b/crypto/bio/bss_bio.c
@@ -7,9 +7,18 @@
  * for which no specific BIO method is available.
  * See ssl/ssltest.c for some hints on how this can be used. */
 
+/* BIO_DEBUG implies BIO_PAIR_DEBUG */
+#ifdef BIO_DEBUG
+# ifndef BIO_PAIR_DEBUG
+#  define BIO_PAIR_DEBUG
+# endif
+#endif
+
+/* disable assert() unless BIO_PAIR_DEBUG has been defined */
 #ifndef BIO_PAIR_DEBUG
-# undef NDEBUG /* avoid conflicting definitions */
-# define NDEBUG
+# ifndef NDEBUG
+#  define NDEBUG
+# endif
 #endif
 
 #include <assert.h>