remove support for non-ANSI compilation

*** 18,27 ****
--- 18,28 ----
   *
   * CDDL HEADER END
   */
  
  /*
+  * Copyright 2014 Garrett D'Amore <garrett@damore.org>
   * Copyright (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright (c) 2013 by Delphix. All rights reserved.
   */
  
  /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
*** 504,522 ****
          long    sys_rval2;      /* second return value from system call */
  } sysret_t;
  
  #if !defined(_KERNEL)
  
- #if defined(__STDC__)
  extern int      syscall(int, ...);
  extern int      __systemcall(sysret_t *, int, ...);
  extern int      __set_errno(int);
- #else
- extern int      syscall();
- extern int      __systemcall();
- extern int      __set_errno();
- #endif
  
  #endif  /* _KERNEL */
  
  #endif  /* _ASM */
  
--- 505,517 ----