Pass PIP_FIND_LINKS through sudo to pip

We weren't actually using the wheels since PIP_FIND_LINKS environmental
variable was getting lost during the sudo

Change-Id: I4a89a70df63772a16ee5a8c3f1cd86e9c7bb5242
diff --git a/inc/python b/inc/python
index dfc4d63..d72c3c9 100644
--- a/inc/python
+++ b/inc/python
@@ -97,6 +97,7 @@
         http_proxy=${http_proxy:-} \
         https_proxy=${https_proxy:-} \
         no_proxy=${no_proxy:-} \
+        PIP_FIND_LINKS=$PIP_FIND_LINKS \
         $cmd_pip install \
         $@
 
@@ -108,6 +109,7 @@
                 http_proxy=${http_proxy:-} \
                 https_proxy=${https_proxy:-} \
                 no_proxy=${no_proxy:-} \
+                PIP_FIND_LINKS=$PIP_FIND_LINKS \
                 $cmd_pip install \
                 -r $test_req
         fi