Only call getauxval(3) if HAVE_GETAUXVAL is defined. Fixes build on older

Linux (such as Ubuntu 12.04LTS) that don't have it yet.  Seems the AT_XXX
defines are pulled in by <link.h> now.
ok beck@

src/lib/libcrypto/arc4random/getentropy_linux.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: getentropy_linux.c,v 1.24 2014/07/13 13:37:38 deraadt Exp $	*/
+/*	$OpenBSD: getentropy_linux.c,v 1.25 2014/07/16 14:26:47 kettenis Exp $	*/
 
 /*
  * Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org>
@@ -486,6 +486,7 @@ getentropy_fallback(void *buf, size_t len)
 
 			HD(cnt);
 		}
+#ifdef HAVE_GETAUXVAL
 #ifdef AT_RANDOM
 		/* Not as random as you think but we take what we are given */
 		p = (char *) getauxval(AT_RANDOM);
@@ -501,6 +502,7 @@ getentropy_fallback(void *buf, size_t len)
 		p = (char *) getauxval(AT_BASE);
 		if (p)
 			HD(p);
+#endif
 #endif
 
 		SHA512_Final(results, &ctx);

src/lib/libcrypto/crypto/getentropy_linux.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: getentropy_linux.c,v 1.24 2014/07/13 13:37:38 deraadt Exp $	*/
+/*	$OpenBSD: getentropy_linux.c,v 1.25 2014/07/16 14:26:47 kettenis Exp $	*/
 
 /*
  * Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org>
@@ -486,6 +486,7 @@ getentropy_fallback(void *buf, size_t len)
 
 			HD(cnt);
 		}
+#ifdef HAVE_GETAUXVAL
 #ifdef AT_RANDOM
 		/* Not as random as you think but we take what we are given */
 		p = (char *) getauxval(AT_RANDOM);
@@ -501,6 +502,7 @@ getentropy_fallback(void *buf, size_t len)
 		p = (char *) getauxval(AT_BASE);
 		if (p)
 			HD(p);
+#endif
 #endif
 
 		SHA512_Final(results, &ctx);