package/vsftpd: set VSFTPD_CPE_ID_VALID

cpe:2.3:a:vsftpd_project:vsftpd is a valid CPE identifier for this
package:

  https://nvd.nist.gov/products/cpe/search/results?namingFormat=2.3&keyword=cpe%3A2.3%3Aa%3Avsftpd_project%3Avsftpd

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/vsftpd/vsftpd.mk

@@ -9,6 +9,7 @@ VSFTPD_SITE = https://security.appspot.com/downloads
 VSFTPD_LIBS = -lcrypt
 VSFTPD_LICENSE = GPL-2.0
 VSFTPD_LICENSE_FILES = COPYING
+VSFTPD_CPE_ID_VALID = YES
 
 define VSFTPD_DISABLE_UTMPX
 	$(SED) 's/.*VSF_BUILD_UTMPX/#undef VSF_BUILD_UTMPX/' $(@D)/builddefs.h