drop references to src/scripts/lib/

Since the lib subdir is empty now (all files have been deleted or moved),
referencing it in the Python search path doesn't make sense.  Drop it.

BUG=None
TEST=precq passes

Change-Id: I7affb19d76801f94c6e1372c864bdcf787d7334d
Reviewed-on: https://chromium-review.googlesource.com/1499908
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
diff --git a/au_test_harness/cros_au_test_harness.py b/au_test_harness/cros_au_test_harness.py
index b5b0f98..c9e94b9 100755
--- a/au_test_harness/cros_au_test_harness.py
+++ b/au_test_harness/cros_au_test_harness.py
@@ -24,7 +24,6 @@
 import errno
 
 import constants
-sys.path.append(constants.CROSUTILS_LIB_DIR)
 sys.path.append(constants.CROS_PLATFORM_ROOT)
 sys.path.append(constants.SOURCE_ROOT)
 
diff --git a/ctest/ctest.py b/ctest/ctest.py
index b090f3d..c68da93 100755
--- a/ctest/ctest.py
+++ b/ctest/ctest.py
@@ -14,7 +14,6 @@
 import sys
 
 import constants
-sys.path.append(constants.CROSUTILS_LIB_DIR)
 sys.path.append(constants.SOURCE_ROOT)
 sys.path.append(constants.CROS_PLATFORM_ROOT)
 
diff --git a/generate_test_payloads/cros_generate_test_payloads.py b/generate_test_payloads/cros_generate_test_payloads.py
index 793ebb8..bf8b418 100755
--- a/generate_test_payloads/cros_generate_test_payloads.py
+++ b/generate_test_payloads/cros_generate_test_payloads.py
@@ -29,7 +29,6 @@
 import tempfile
 
 import constants
-sys.path.append(constants.CROSUTILS_LIB_DIR)
 sys.path.append(constants.CROS_PLATFORM_ROOT)
 sys.path.append(constants.SOURCE_ROOT)
 
diff --git a/lib/constants.py b/lib/constants.py
index 75eb113..45b451d 100644
--- a/lib/constants.py
+++ b/lib/constants.py
@@ -22,6 +22,4 @@
 
 CROSUTILS_DIR = os.path.join(SOURCE_ROOT, 'src', 'scripts')
 
-CROSUTILS_LIB_DIR = os.path.join(CROSUTILS_DIR, 'lib')
-
 MAX_TIMEOUT_SECONDS = 4800