1.change inline usage in code and mvec in makefile to adapt to GCC version
in Yacto
2. refine the doc to include each libs quick build command

Signed-off-by: Zhimin<zhimin.yuan@intel.com>
Change-Id: Id1f3f9e5b7a40239e8905db130995090befd462d
diff --git a/docs/build_prerequisite.rst b/docs/build_prerequisite.rst
index a4f018f..411bb55 100644
--- a/docs/build_prerequisite.rst
+++ b/docs/build_prerequisite.rst
@@ -1,4 +1,4 @@
-..    Copyright (c) 2019 Intel
+..    Copyright (c) 2019 Intel
 ..
 ..  Licensed under the Apache License, Version 2.0 (the "License");
 ..  you may not use this file except in compliance with the License.
@@ -77,15 +77,16 @@
 
    - build DPDK
       build DPDK::
-
+        Set your ICC installation path to /usertools/dpdk-setup.sh, DEFAULT_PATH="your ICC installation path"/bin/iccvars.sh, then run it to build DPDK with below option. 
         #./usertools/dpdk-setup.sh
         select [39] x86_64-native-linuxapp-icc
         exit   [62] Exit Script
-
-   - set DPDK path
+        please pay attention, the number 39 might change in your setup, you need choose accordingly to option 'x86_64-native-linuxapp-icc'   
+  
+    - set DPDK path
        DPDK path is needed during build and run lib/app::
 
-        #export RTE_SDK=Intallation_DIR/dpdk-19.11
+        #export RTE_SDK=Installation_DIR/dpdk-19.11
         #export DESTDIR=Installation_DIR/dpdk-19.11