MIPS: BCM47XX: Don't try guessing NVRAM size on MTD partition

When dealing with whole flash content (bcm47xx_nvram_init_from_mem) we
need to find NVRAM start trying various partition sizes (nvram_sizes).
This is not needed when using MTD as we have direct partition access.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: https://patchwork.linux-mips.org/patch/9652/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/bcm47xx/nvram.c

@@ -139,20 +139,13 @@ static int nvram_init(void)
 	struct mtd_info *mtd;
 	struct nvram_header header;
 	size_t bytes_read;
-	int err, i;
+	int err;
 
 	mtd = get_mtd_device_nm("nvram");
 	if (IS_ERR(mtd))
 		return -ENODEV;
 
-	for (i = 0; i < ARRAY_SIZE(nvram_sizes); i++) {
-		loff_t from = mtd->size - nvram_sizes[i];
-
-		if (from < 0)
-			continue;
-
-		err = mtd_read(mtd, from, sizeof(header), &bytes_read,
-			       (uint8_t *)&header);
+	err = mtd_read(mtd, 0, sizeof(header), &bytes_read, (uint8_t *)&header);
 	if (!err && header.magic == NVRAM_MAGIC) {
 		u8 *dst = (uint8_t *)nvram_buf;
 		size_t len = header.len;
@@ -163,13 +156,12 @@ static int nvram_init(void)
 			len = NVRAM_SPACE;
 		}
 
-			err = mtd_read(mtd, from, len, &bytes_read, dst);
+		err = mtd_read(mtd, 0, len, &bytes_read, dst);
 		if (err)
 			return err;
 
 		return 0;
 	}
-	}
 #endif
 
 	return -ENXIO;