build: Explicitly use bash for shell scripts

VPP requires bash for all shell scripts. Align shebang lines in build
and test scripts to look up the location of bash rather than hard coding
'/bin/bash'.

Look up the location of bash for makefiles.

Type: improvement
Change-Id: I23b705d81d60389fa8af61c680cf0abd74f0ea24
Signed-off-by: Tom Jones <thj@freebsd.org>

extras/vagrant/build.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Get Command Line arguements if present
 VPP_DIR=$1

extras/vagrant/clearinterfaces.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Capture all the interface IPs, in case we need them later
 ip -o addr show > ~vagrant/ifconfiga

extras/vagrant/install.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Get Command Line arguements if present
 VPP_DIR=$1

extras/vagrant/run.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Figure out what system we are running on
 if [ "$(uname)" <> "Darwin" ] ; then

extras/vagrant/update.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Make sure that we get the hugepages we need on provision boot
 # Note: The package install should take care of this at the end

extras/vagrant/vcl_test.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 if [ -n "$1" ]; then
     VPP_DIR=$1