finish build_target_lib.get_default_sysroot_path migration [reland]

This allows us to drop the build_target_lib import from cros_build_lib.

The failing platform2 code that caused this to revert before has been
fixed, and cs/ doesn't show any other latent hits.

BUG=chromium:1170007
TEST=CQ passes

Change-Id: I284d99fc2570eff7c4e843140efdfe5a56acc8d5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2814898
Tested-by: Mike Frysinger <vapier@chromium.org>
Auto-Submit: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Sergey Frolov <sfrolov@google.com>
Reviewed-by: Sergey Frolov <sfrolov@google.com>
diff --git a/cli/deploy.py b/cli/deploy.py
index 058bcfa..8d01e60 100644
--- a/cli/deploy.py
+++ b/cli/deploy.py
@@ -21,6 +21,7 @@
 import tempfile
 
 from chromite.cli import command
+from chromite.lib import build_target_lib
 from chromite.lib import cros_build_lib
 from chromite.lib import cros_logging as logging
 from chromite.lib import dlc_lib
@@ -1199,7 +1200,7 @@
         raise DeployError('Device (%s) is incompatible with board %s. Use '
                           '--force to deploy anyway.' % (device.board, board))
 
-      sysroot = cros_build_lib.GetSysroot(board=board)
+      sysroot = build_target_lib.get_default_sysroot_path(board)
 
       # Don't bother trying to clean for unmerges.  We won't use the local db,
       # and it just slows things down for the user.