rootfs-postcommands: add test for unsatisfied RRECOMMENDS

The do_rootfs log contains a number of unsatisfied package
recommendations. At the moment those are only visible when
reviewing the rootfs log.

This patch adds an extra check to surface any unsatisfied
recommendation  as WARNINGS to the build output.

Enable this check with:
ROOTFS_POSTPROCESS_COMMAND += "rootfs_log_check_recommends;"

(From OE-Core rev: 9d049bf7941f30e35c51775684559e95185fba96)

Signed-off-by: Jose Alarcon <jose.alarcon@ge.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/rootfs-postcommands.bbclass

@@ -307,3 +307,15 @@ python write_image_test_data() {
            os.remove(testdata_link)
         os.symlink(os.path.basename(testdata), testdata_link)
 }
+
+# Check for unsatisfied recommendations (RRECOMMENDS)
+python rootfs_log_check_recommends() {
+    log_path = d.expand("${T}/log.do_rootfs")
+    with open(log_path, 'r') as log:
+        for line in log:
+            if 'log_check' in line:
+                continue
+
+            if 'unsatisfied recommendation for' in line:
+                bb.warn('[log_check] %s: %s' % (d.getVar('PN', True), line))
+}