check_whence: error if File: is actually a link

Commits from a few years ago added support for Link entries, over having
the symlinks in-tree.

At the same time, it didn't add a check whether one didn't add a File
entry that is actually a symlink. Do so now, to be on the safe side.

v2:
 - drop copy-firmware.sh changes

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Signed-off-by: Josh Boyer <jwboyer@kernel.org>

check_whence.py

@@ -60,6 +60,11 @@ def main():
         sys.stderr.write('E: %s listed in WHENCE twice\n' % name)
         ret = 1
 
+    for name in set(link for link in whence_files if os.path.islink(link)):
+        sys.stderr.write('E: %s listed in WHENCE as File, but is a symlink\n' %
+                         name)
+        ret = 1
+
     for name in sorted(list(known_files - git_files)):
         sys.stderr.write('E: %s listed in WHENCE does not exist\n' % name)
         ret = 1