11859 need swapgs mitigation
Reviewed by: Robert Mustacchi <rm@fingolfin.org>
Reviewed by: Dan McDonald <danmcd@joyent.com>
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Robert Mustacchi <rm@fingolfin.org>

@@ -170,21 +170,10 @@
             "movw       %0, %%gs"
             : /* no output */
             : "r" (value));
 }
 
-#if !defined(__xpv)
-
-extern __GNU_INLINE void
-__swapgs(void)
-{
-        __asm__ __volatile__(
-            "mfence; swapgs");
-}
-
-#endif /* !__xpv */
-
 #endif  /* __amd64 */
 
 #endif  /* !__lint && __GNUC__ */
 
 #ifdef  __cplusplus