Use ANSI C definitions, update comment.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week

libexec/rtld-elf/rtld_lock.c

@@ -38,8 +38,8 @@
  * In this algorithm the lock is a single word.  Its low-order bit is
  * set when a writer holds the lock.  The remaining high-order bits
  * contain a count of readers desiring the lock.  The algorithm requires
- * atomic "compare_and_store" and "add" operations, which we implement
- * using assembly language sequences in "rtld_start.S".
+ * atomic "compare_and_store" and "add" operations, which we take
+ * from machine/atomic.h.
  */
 
 #include <sys/param.h>
@@ -67,7 +67,7 @@ static sigset_t fullsigmask, oldsigmask;
 static int thread_flag;
 
 static void *
-def_lock_create()
+def_lock_create(void)
 {
     void *base;
     char *p;
@@ -269,7 +269,7 @@ lock_restart_for_upgrade(RtldLockState *lockstate)
 }
 
 void
-lockdflt_init()
+lockdflt_init(void)
 {
     int i;