Revert "Add ability to check /etc/lsb-release for HWID"

This reverts commit d1da5101a191aa90fd671c9b9ab36573849a08e2.

Investigating a parrot in this state (from the bug) I discovered that if I specified HWID_OVERRIDE=tacos, hardware_class=tacos got sent in the omaha request. This must be an issue with either us passing define incorrectly or parsing it incorrectly. Reverting for now to be safe. 

BUG=chromium:344727
TEST=tested manually that the reason the bug is happening is because update_engine is respecting HWID_OVERRIDE

Change-Id: I18665abc93a8d88b1d73f56c1784971ff0d29b87
Reviewed-on: https://chromium-review.googlesource.com/187029
Reviewed-by: Chris Sosa <sosa@chromium.org>
Tested-by: Chris Sosa <sosa@chromium.org>
diff --git a/extent_writer_unittest.cc b/extent_writer_unittest.cc
index 55cbff6..f0f5f7a 100644
--- a/extent_writer_unittest.cc
+++ b/extent_writer_unittest.cc
@@ -40,7 +40,7 @@
   }
   int fd() { return fd_; }
   const char* path() { return path_; }
-
+  
   // Writes data to an extent writer in 'chunk_size' chunks with
   // the first chunk of size first_chunk_size. It calculates what the
   // resultant file should look like and ensure that the extent writer