support/scripts/pkg-stats: properly handle host packages with -c option

In commit 7a607dab336e7f78ab069cff1b503d0688950583
("support/scripts/pkg-stats: support generating stats based on
configured packages"), we added a -c option to pkg-stats to generate a
report based on the list of packages enabled in the configuration,
rather than for all packages.

This is done based on the list of packages returned in JSON format by
"make show-info". However, we use the keys of the JSON dict returned
by "make show-info", which include the host- prefix of host
packages. Due to this, none of the host packages are currently
matching and therefore they are not reported in the pkg-stats -c
output.

This commit fixes that by using the recently introduced "name"
property in the "make show-info" JSON dict.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
[yann.morin.1998@free.fr: use anonymous '_' for unused variable]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

support/scripts/pkg-stats

@@ -358,7 +358,7 @@ def get_pkglist(npackages, package_list):
 def get_config_packages():
     cmd = ["make", "--no-print-directory", "show-info"]
     js = json.loads(subprocess.check_output(cmd))
-    return js.keys()
+    return set([v["name"] for _, v in js.items()])
 
 
 def package_init_make_info():