mtd: mtdswap: fix spelling mistake "erassure" -> "erasure"

Trivial fix to spelling mistake in dev_err message

Signed-off-by: Colin Ian King <colin.king@canonical.com>
[Brian: add EOL newline]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/mtdswap.c

@@ -587,7 +587,7 @@ retry:
 	ret = wait_event_interruptible(wq, erase.state == MTD_ERASE_DONE ||
 					   erase.state == MTD_ERASE_FAILED);
 	if (ret) {
-		dev_err(d->dev, "Interrupted erase block %#llx erassure on %s",
+		dev_err(d->dev, "Interrupted erase block %#llx erasure on %s\n",
 			erase.addr, mtd->name);
 		return -EINTR;
 	}