package/libs/libjson-c: fix PKG_CPE_ID

cpe:/a:json-c:json-c is the correct CPE ID for libjson-c:
https://nvd.nist.gov/products/cpe/search/results?keyword=cpe:2.3:a:json-c:json-c



Fixes: c61a2395 (add PKG_CPE_ID ids to package and tools)

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/15292


Signed-off-by: Robert Marko <robimarko@gmail.com>
(cherry picked from commit a4f723e04ed245819fe320f472a4ff2b4eda00fb)
Link: https://github.com/openwrt/openwrt/pull/15881


Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

package/libs/libjson-c/Makefile

@@ -18,7 +18,7 @@ PKG_HASH:=ac8a3dd6820daaca579b23fbc74664310fbc3d67f52f6707cda67d21dde5570f
 PKG_MAINTAINER:=Felix Fietkau <nbd@nbd.name>
 PKG_LICENSE:=MIT
 PKG_LICENSE_FILES:=COPYING
-PKG_CPE_ID:=cpe:/a:json-c_project:json-c
+PKG_CPE_ID:=cpe:/a:json-c:json-c
 
 HOST_BUILD_PREFIX:=$(STAGING_DIR_HOST)