[PATCH] license: Improve disk usage

[Richard Purdie <richard.purdie@linuxfoundation.org>]

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.

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

diff --git a/meta/classes/license.bbclass b/meta/classes/license.bbclass
index 601f561..a34ea39 100644
--- a/meta/classes/license.bbclass
+++ b/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))