9971 Make getrandom(2) a public interface

@@ -8,17 +8,17 @@
  * source.  A copy of the CDDL is also available via the Internet at
  * http://www.illumos.org/license/CDDL.
  */
 
 /*
- * Copyright (c) 2015 Joyent, Inc.
+ * Copyright (c) 2018 Joyent, Inc.
  */
 
 #include <sys/types.h>
 #include <sys/syscall.h>
 #include <sys/random.h>
 
-int
-getrandom(void *buf, size_t len, int flags)
+ssize_t
+getrandom(void *buf, size_t len, unsigned int flags)
 {
         return (syscall(SYS_getrandom, buf, len, flags));
 }