RAND_set_rand_method takes a const parameter.

Change-Id: I37e7c00deeb74aa0b71ee0d3a242d33d4d413cf0
diff --git a/include/openssl/rand.h b/include/openssl/rand.h
index 4e0c9af..a43505a 100644
--- a/include/openssl/rand.h
+++ b/include/openssl/rand.h
@@ -72,7 +72,7 @@
 OPENSSL_EXPORT RAND_METHOD *RAND_SSLeay(void);
 
 /* RAND_set_rand_method does nothing. */
-OPENSSL_EXPORT void RAND_set_rand_method(RAND_METHOD *);
+OPENSSL_EXPORT void RAND_set_rand_method(const RAND_METHOD *);
 
 
 #if defined(__cplusplus)