Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c
index f29a6f9..97183c8 100644
--- a/drivers/mtd/devices/block2mtd.c
+++ b/drivers/mtd/devices/block2mtd.c
@@ -295,7 +295,7 @@
 	dev->mtd.owner = THIS_MODULE;
 
 	if (add_mtd_device(&dev->mtd)) {
-		/* Device didnt get added, so free the entry */
+		/* Device didn't get added, so free the entry */
 		goto devinit_err;
 	}
 	list_add(&dev->list, &blkmtd_device_list);