Fix structure alignment with 32-bit pointers

Change-Id: I740de6c0f12dab452b4349e3bf89ff976a6268c0
Signed-off-by: Damjan Marion <damarion@cisco.com>
diff --git a/src/vlib/node.h b/src/vlib/node.h
index 1e2f4c3..906d795 100644
--- a/src/vlib/node.h
+++ b/src/vlib/node.h
@@ -418,6 +418,10 @@
 
   vlib_error_t *errors;			/**< Vector of errors for this node. */
 
+#if __SIZEOF_POINTER__ == 4
+  u8 pad[8];
+#endif
+
   u32 clocks_since_last_overflow;	/**< Number of clock cycles. */
 
   u32 max_clock;			/**< Maximum clock cycle for an