5042 stop using deprecated atomic functions

*** 162,176 ****
          if (enabled) {
                  ASSERT(sysent[sysnum].sy_callc == dtrace_systrace_syscall);
                  return (0);
          }
  
!         (void) casptr(&sysent[sysnum].sy_callc,
              (void *)systrace_sysent[sysnum].stsy_underlying,
              (void *)dtrace_systrace_syscall);
  #ifdef _SYSCALL32_IMPL
!         (void) casptr(&sysent32[sysnum].sy_callc,
              (void *)systrace_sysent32[sysnum].stsy_underlying,
              (void *)dtrace_systrace_syscall32);
  #endif
          return (0);
  }
--- 162,176 ----
          if (enabled) {
                  ASSERT(sysent[sysnum].sy_callc == dtrace_systrace_syscall);
                  return (0);
          }
  
!         (void) atomic_cas_ptr(&sysent[sysnum].sy_callc,
              (void *)systrace_sysent[sysnum].stsy_underlying,
              (void *)dtrace_systrace_syscall);
  #ifdef _SYSCALL32_IMPL
!         (void) atomic_cas_ptr(&sysent32[sysnum].sy_callc,
              (void *)systrace_sysent32[sysnum].stsy_underlying,
              (void *)dtrace_systrace_syscall32);
  #endif
          return (0);
  }
*** 182,197 ****
          int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg);
          int disable = (systrace_sysent[sysnum].stsy_entry == DTRACE_IDNONE ||
              systrace_sysent[sysnum].stsy_return == DTRACE_IDNONE);
  
          if (disable) {
!                 (void) casptr(&sysent[sysnum].sy_callc,
                      (void *)dtrace_systrace_syscall,
                      (void *)systrace_sysent[sysnum].stsy_underlying);
  
  #ifdef _SYSCALL32_IMPL
!                 (void) casptr(&sysent32[sysnum].sy_callc,
                      (void *)dtrace_systrace_syscall32,
                      (void *)systrace_sysent32[sysnum].stsy_underlying);
  #endif
          }
  
--- 182,197 ----
          int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg);
          int disable = (systrace_sysent[sysnum].stsy_entry == DTRACE_IDNONE ||
              systrace_sysent[sysnum].stsy_return == DTRACE_IDNONE);
  
          if (disable) {
!                 (void) atomic_cas_ptr(&sysent[sysnum].sy_callc,
                      (void *)dtrace_systrace_syscall,
                      (void *)systrace_sysent[sysnum].stsy_underlying);
  
  #ifdef _SYSCALL32_IMPL
!                 (void) atomic_cas_ptr(&sysent32[sysnum].sy_callc,
                      (void *)dtrace_systrace_syscall32,
                      (void *)systrace_sysent32[sysnum].stsy_underlying);
  #endif
          }