2976 remove useless offsetof() macros

@@ -28,18 +28,16 @@
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+#include <sys/sysmacros.h>
 
 #include <sys/ib/clients/of/sol_ofs/sol_ofs_common.h>
 #include <sys/ib/clients/of/rdma/rdma_cm.h>
 #include <sys/ib/clients/of/sol_ofs/sol_ib_cma.h> /* Transport Specific */
 
-#if !defined(offsetof)
-#define offsetof(s, m)          (size_t)(&(((s *)0)->m))
-#endif
 
 #define IS_UDP_CMID(idp)        ((idp)->ps == RDMA_PS_UDP || \
         (idp)->ps == RDMA_PS_IPOIB)
 #define IS_VALID_SOCKADDR(sockaddrp) \
         ((sockaddrp)->sa_family == AF_INET || \