Use better packing of leak-detective memory_header to align pointers

src/libstrongswan/utils/leak_detective.c

@@ -92,11 +92,6 @@ typedef struct memory_tail_t memory_tail_t;
  */
 struct memory_header_t {
 
-	/**
-	 * Number of bytes following after the header
-	 */
-	u_int bytes;
-
 	/**
 	 * Pointer to previous entry in linked list
 	 */
@@ -112,6 +107,11 @@ struct memory_header_t {
 	 */
 	backtrace_t *backtrace;
 
+	/**
+	 * Number of bytes following after the header
+	 */
+	u_int32_t bytes;
+
 	/**
 	 * magic bytes to detect bad free or heap underflow, MEMORY_HEADER_MAGIC
 	 */