cve-check.bbclass: make warning contain CVE IDs

When warning users about unpatched CVE, we'd better put CVE IDs into
the warning message, so that it would be more straight forward for the
user to know which CVEs are not patched.

So instead of:
  WARNING: gnutls-3.5.9-r0 do_cve_check: Found unpatched CVE, for more information check /path/to/workdir/cve/cve.log.
We should have:
  WARNING: gnutls-3.5.9-r0 do_cve_check: Found unpatched CVE (CVE-2017-7869), for more information check /path/to/workdir/cve/cve.log.

(From OE-Core rev: ad46069e7b58f2fba373131716f28407816fa1a6)

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/cve-check.bbclass

@@ -234,7 +234,7 @@ def cve_write_data(d, patched, unpatched, cve_data):
     cve_file = d.getVar("CVE_CHECK_LOCAL_FILE")
     nvd_link = "https://web.nvd.nist.gov/view/vuln/detail?vulnId="
     write_string = ""
-    first_alert = True
+    unpatched_cves = []
     bb.utils.mkdirhier(d.getVar("CVE_CHECK_LOCAL_DIR"))
 
     for cve in sorted(cve_data):
@@ -244,15 +244,16 @@ def cve_write_data(d, patched, unpatched, cve_data):
         if cve in patched:
             write_string += "CVE STATUS: Patched\n"
         else:
+            unpatched_cves.append(cve)
             write_string += "CVE STATUS: Unpatched\n"
-            if first_alert:
-                bb.warn("Found unpatched CVE, for more information check %s" % cve_file)
-                first_alert = False
         write_string += "CVE SUMMARY: %s\n" % cve_data[cve]["summary"]
         write_string += "CVSS v2 BASE SCORE: %s\n" % cve_data[cve]["score"]
         write_string += "VECTOR: %s\n" % cve_data[cve]["vector"]
         write_string += "MORE INFORMATION: %s%s\n\n" % (nvd_link, cve)
 
+    if unpatched_cves:
+        bb.warn("Found unpatched CVE (%s), for more information check %s" % (" ".join(unpatched_cves),cve_file))
+
     with open(cve_file, "w") as f:
         bb.note("Writing file %s with CVE information" % cve_file)
         f.write(write_string)