use method pip_install over sudo pip install so proxy settings work

Change-Id: I2f0c69a72ef73c317b707d99c65cab0fb590d158
diff --git a/tools/fixup_stuff.sh b/tools/fixup_stuff.sh
index 371b25f..87922c8 100755
--- a/tools/fixup_stuff.sh
+++ b/tools/fixup_stuff.sh
@@ -34,8 +34,8 @@
 # ---------------
 
 # Pre-install affected packages so we can fix the permissions
-sudo pip install prettytable
-sudo pip install httplib2
+pip_install prettytable
+pip_install httplib2
 
 SITE_DIRS=$(python -c "import site; import os; print os.linesep.join(site.getsitepackages())")
 for dir in $SITE_DIRS; do