Fix issue5 for endian safe

Make eSEL request data be endian-safe.
Redefine the struct of esel_request_t.
Use le16toh() of <endian.h>

Signed-off-by: Nan Li <bjlinan@cn.ibm.com>
diff --git a/oemhandler.h b/oemhandler.h
index 71ae01c..1c8a97e 100644
--- a/oemhandler.h
+++ b/oemhandler.h
@@ -20,12 +20,9 @@
 
 
 struct esel_request_t {
-    uint8_t  residls;
-    uint8_t  residms;
-    uint8_t  selrecordls;
-    uint8_t  selrecordms;
-    uint8_t  offsetls;
-    uint8_t  offsetms;
+    uint16_t  resid;
+    uint16_t  selrecord;
+    uint16_t  offset;
     uint8_t  progress;
 }  __attribute__ ((packed)) ;