hcrypto: Export hc_RAND_bytes

Export the RAND_bytes function from hcrypto, so that we can have
access to hcrypto's random number generator from generic code.

Change-Id: Ie46bdf0b7818b10f0311ae3029c27a15382ffd7a
Reviewed-on: http://gerrit.openafs.org/7975
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>

src/crypto/hcrypto/libafshcrypto.map

@@ -21,6 +21,7 @@
 	hc_MD5_Final;
 	hc_MD5_Init;
 	hc_MD5_Update;
+	hc_RAND_bytes;
 	hc_UI_UTIL_read_pw_string;
     local:
 	*;