brcm63xx: remove misleading warning about partial SPI NOR writes

The warning will be triggered by jffs2 or UBI, and partial writes are no
issue for most flash chips.

Fixes: 2a2b16210b ("brcm63xx: backport upstream solution for SPI message size limits")
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>

target/linux/brcm63xx/patches-4.4/001-4.11-02-mtd-spi-nor-remove-WARN_ONCE-message-in-spi_nor_writ.patch

@@ -0,0 +1,33 @@
+From bc0e151514d09cadb56e473a10c783e64e48ce0b Mon Sep 17 00:00:00 2001
+From: Cyrille Pitchen <cyrille.pitchen@atmel.com>
+Date: Tue, 6 Dec 2016 18:14:24 +0100
+Subject: [PATCH] mtd: spi-nor: remove WARN_ONCE() message in spi_nor_write()
+
+This patch removes the WARN_ONCE() test in spi_nor_write().
+This macro triggers the display of a warning message almost every time we
+use a UBI file-system because a write operation is performed at offset 64,
+which is in the middle of the SPI NOR memory page. This is a valid
+operation for ubifs.
+
+Hence this warning is pretty annoying and useless so we just remove it.
+
+Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
+Suggested-by: Richard Weinberger <richard@nod.at>
+Suggested-by: Andras Szemzo <szemzo.andras@gmail.com>
+Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
+---
+ drivers/mtd/spi-nor/spi-nor.c | 3 ---
+ 1 file changed, 3 deletions(-)
+
+--- a/drivers/mtd/spi-nor/spi-nor.c
++++ b/drivers/mtd/spi-nor/spi-nor.c
+@@ -1014,9 +1014,6 @@ static int spi_nor_write(struct mtd_info
+ 		ssize_t written;
+ 
+ 		page_offset = (to + i) & (nor->page_size - 1);
+-		WARN_ONCE(page_offset,
+-			  "Writing at offset %zu into a NOR page. Writing partial pages may decrease reliability and increase wear of NOR flash.",
+-			  page_offset);
+ 		/* the size of data remaining on the first page */
+ 		page_remain = min_t(size_t,
+ 				    nor->page_size - page_offset, len - i);