dpkg: fix CONFIG_FEATURE_CLEAN_UP handling

dpkg moved to away from dynamically allocating the hashtables in commit
c87339d584 (dpkg: trivial code shrinkage, and redo G trick correctly) almost
ten years ago, but the cleanup code was never adjusted to match.

Glibc loudly complains about this:

*** Error in `dpkg': free(): invalid pointer: 0x0000007fac3478c0 ***

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

archival/dpkg.c

@@ -1938,10 +1938,6 @@ int dpkg_main(int argc UNUSED_PARAM, char **argv)
 		for (i = 0; i < STATUS_HASH_PRIME; i++) {
 			free(status_hashtable[i]);
 		}
-
-		free(status_hashtable);
-		free(package_hashtable);
-		free(name_hashtable);
 	}
 
 	return EXIT_SUCCESS;