NEX-3079 port illumos ARC improvements

@@ -651,11 +651,11 @@
         if (flags & ZINJECT_FLUSH_ARC)
                 /*
                  * We must use FALSE to ensure arc_flush returns, since
                  * we're not preventing concurrent ARC insertions.
                  */
-                arc_flush(NULL, FALSE);
+                arc_flush(NULL, B_FALSE);
 
         return (0);
 }
 
 /*