Tools: install-prereqs: do not use sudo to install Python packages

Tools/scripts/install-prereqs-arch.sh

@@ -33,8 +33,8 @@ function prompt_user() {
 sudo usermod -a -G uucp $USER
 
 sudo pacman -Sy --noconfirm --needed $BASE_PKGS $SITL_PKGS $PX4_PKGS
-sudo pip2 -q install -U $PYTHON2_PKGS
-sudo pip3 -q install -U $PYTHON3_PKGS
+pip2 -q install --user -U $PYTHON2_PKGS
+pip3 -q install --user -U $PYTHON3_PKGS
 
 (
     cd /usr/lib/ccache

Tools/scripts/install-prereqs-mac.sh

@@ -26,7 +26,7 @@ else
     echo "pip installed"
 fi
 
-sudo pip2 install pyserial future empy mavproxy
+pip2 install --user pyserial future empy mavproxy
 
 SCRIPT_DIR=$(dirname $(realpath ${BASH_SOURCE[0]}))
 ARDUPILOT_ROOT=$(realpath "$SCRIPT_DIR/../../")

Tools/scripts/install-prereqs-ubuntu.sh

@@ -97,7 +97,7 @@ if [ -n "$RP" ]; then
 fi
 
 $APT_GET install $BASE_PKGS $SITL_PKGS $PX4_PKGS $ARM_LINUX_PKGS
-sudo pip2 -q install -U $PYTHON_PKGS
+pip2 -q install --user -U $PYTHON_PKGS
 
 if [ ! -d $OPT/$ARM_ROOT ]; then
     (