Fix typos in doc and comments

Changes persistant -> persistent. www.dictionary.com does not know
persistant (with an A), but should it be one of those things you can
spell in more than one correct way, let me know.

Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/drivers/mtd/maps/cfi_flagadm.c b/drivers/mtd/maps/cfi_flagadm.c
index 92b5d88..65e5ee5 100644
--- a/drivers/mtd/maps/cfi_flagadm.c
+++ b/drivers/mtd/maps/cfi_flagadm.c
@@ -80,7 +80,7 @@
 		.size =		FLASH_PARTITION2_SIZE
 	},
 	{
-		.name =		"Persistant storage",
+		.name =		"Persistent storage",
 		.offset =	FLASH_PARTITION3_ADDR,
 		.size =		FLASH_PARTITION3_SIZE
 	}