license: Improve disk usage

Currently copies of the license files are made which wastes disk space
and adversely affects performance. We can link these instead in most
cases for small performance gains.

(From OE-Core rev: 0b0f3631fd22f731b6aeedb73965e367b695028b)

(From OE-Core rev: fe00d4f479c4fb5e4be5dda616a4de0a257ef6c3)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/license.bbclass

@@ -145,7 +145,14 @@ def copy_license_files(lic_files_paths, destdir):
     bb.utils.mkdirhier(destdir)
     for (basename, path) in lic_files_paths:
         try:
-            ret = shutil.copyfile(path, os.path.join(destdir, basename))
+            src = path
+            dst = os.path.join(destdir, basename)
+            if os.path.exists(dst):
+                os.remove(dst)
+            if (os.stat(src).st_dev == os.stat(destdir).st_dev):
+                os.link(src, dst)
+            else:
+                shutil.copyfile(src, dst)
         except Exception as e:
             bb.warn("Could not copy license file %s: %s" % (basename, e))