shill: update Makefile to enable -Wall, and related flags, on ebuilds

Previously, ebuild flags would be used in preference to those in
the Makefile. Now, we append -Wall, and related flags, to those
set by emake.

Also: update existing code to eliminate warnings.

BUG=chromium-os:15877
TEST=emerge

Change-Id: I95f80860edb29e197aef0e08493f78276da3c062
Reviewed-on: http://gerrit.chromium.org/gerrit/1742
Reviewed-by: Chris Masone <cmasone@chromium.org>
Tested-by: mukesh agrawal <quiche@chromium.org>
diff --git a/device.cc b/device.cc
index d1a037c..1f196ce 100644
--- a/device.cc
+++ b/device.cc
@@ -37,11 +37,11 @@
                int interface_index)
     : powered_(true),
       reconnect_(true),
+      interface_index_(interface_index),
+      running_(false),
       manager_(manager),
       link_name_(link_name),
-      adaptor_(control_interface->CreateDeviceAdaptor(this)),
-      interface_index_(interface_index),
-      running_(false) {
+      adaptor_(control_interface->CreateDeviceAdaptor(this)) {
 
   store_.RegisterConstString(flimflam::kAddressProperty, &hardware_address_);