Remove/fix unused stuff and other warnings

kernel/storedev/atasd.c

@@ -128,7 +128,7 @@ void ata_probe(void) {
       .devno = ATA_MASTER,
       .capacity = probesize,
     };
-    StoreDev *sd = storedev_create(STOREDEV_ATASD, (void *)&extra);
+    storedev_create(STOREDEV_ATASD, (void *)&extra);
   }
 }
 
@@ -211,6 +211,7 @@ done:
 }
 
 int32_t atasd_cleanup(struct StoreDev *sd) {
+  (void)sd;
   return E_OK;
 }