homework: drop unnecessary initialization

src/home/homework-password-cache.c

@@ -16,7 +16,7 @@ void password_cache_free(PasswordCache *cache) {
 void password_cache_load_keyring(UserRecord *h, PasswordCache *cache) {
         _cleanup_(erase_and_freep) void *p = NULL;
         _cleanup_free_ char *name = NULL;
-        char **strv = NULL;
+        char **strv;
         key_serial_t serial;
         size_t sz;
         int r;