target: Copy symlinks as files when pulling

When pulling a file from the target, copy all paths as files and follow
symlinks if necessary. That fixes issues related to chmod not working on
symlinks and generally allows getting any path.

If we want to one day preserve symlinks in some capacities, we can
always add an option to Target.pull() to do so.

Author: douglas-raillard-arm

devlib/target.py

@@ -899,7 +899,7 @@ def do_pull(sources, dest):
             for sources, dest in mapping.items():
                 for source in sources:
                     async with self._xfer_cache_path(source) as device_tempfile:
-                        await self.execute.asyn("cp -r -- {} {}".format(quote(source), quote(device_tempfile)), as_root=as_root)
+                        await self.execute.asyn("cp -rL -- {} {}".format(quote(source), quote(device_tempfile)), as_root=as_root)
                         await self.execute.asyn("{} chmod 0644 -- {}".format(self.busybox, quote(device_tempfile)), as_root=as_root)
                         do_pull([device_tempfile], dest)
         else: