OS-4807 arp(1M) and ndp(1M) should use zone_get_nroot()

*** 38,47 ****
--- 38,48 ----
  #include <netinet/in.h>
  #include <arpa/inet.h>
  #include <inet/ip.h>
  #include <net/if_dl.h>
  #include <net/route.h>
+ #include <zone.h>
  
  typedef struct  sockaddr_in6    sin6_t;
  
  #define BUF_SIZE 2048
  typedef struct rtmsg_pkt {
*** 93,110 ****
  static  int     ndp_set(int, struct lifreq *, void *);
  static  int     ndp_set_nce(char *, char *, char *[], int);
  static  int     ndp_set_file(char *);
  
  static  char            *ndp_iface = NULL;
- static  char            *netstat_path = "/usr/bin/netstat";
  static  pid_t           ndp_pid;
  static  boolean_t       ndp_noresolve = B_FALSE; /* Don't lookup addresses */
  static  boolean_t       ndp_run = B_TRUE;
  
  #define MAX_ATTEMPTS 5
  #define MAX_OPTS 5
  #define WORDSEPS " \t\r\n"
  
  /*
   * Macros borrowed from route(1M) for working with PF_ROUTE messages
   */
  #define RT_ADVANCE(x, n) ((x) += ndp_salen(n))
--- 94,111 ----
  static  int     ndp_set(int, struct lifreq *, void *);
  static  int     ndp_set_nce(char *, char *, char *[], int);
  static  int     ndp_set_file(char *);
  
  static  char            *ndp_iface = NULL;
  static  pid_t           ndp_pid;
  static  boolean_t       ndp_noresolve = B_FALSE; /* Don't lookup addresses */
  static  boolean_t       ndp_run = B_TRUE;
  
  #define MAX_ATTEMPTS 5
  #define MAX_OPTS 5
  #define WORDSEPS " \t\r\n"
+ #define NETSTAT_PATH    "/usr/bin/netstat"
  
  /*
   * Macros borrowed from route(1M) for working with PF_ROUTE messages
   */
  #define RT_ADVANCE(x, n) ((x) += ndp_salen(n))
*** 765,774 ****
--- 766,781 ----
   * Print out all NDP entries
   */
  static void
  ndp_get_all(void)
  {
+         char netstat_path[MAXPATHLEN];
+         const char *zroot = zone_get_nroot();
+ 
+         (void) snprintf(netstat_path, sizeof (netstat_path), "%s%s", zroot != NULL ?
+             zroot : "", NETSTAT_PATH);
+ 
          (void) execl(netstat_path, "netstat",
              (ndp_noresolve ? "-np" : "-p"),
              "-f", "inet6", (char *)0);
          ndp_fatal("Coudn't exec %s: %s", netstat_path, strerror(errno));
  }