mtd: Rename free() to rfree()

This function name conflicts with our desire to #define free() to
something else on sandbox. Since it deals with resources, rename it to
rfree().

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/mtd/nand/raw/denali.c b/drivers/mtd/nand/raw/denali.c
index be1b362..b5a98f5 100644
--- a/drivers/mtd/nand/raw/denali.c
+++ b/drivers/mtd/nand/raw/denali.c
@@ -1156,7 +1156,7 @@
 
 static const struct mtd_ooblayout_ops denali_ooblayout_ops = {
 	.ecc = denali_ooblayout_ecc,
-	.free = denali_ooblayout_free,
+	.rfree = denali_ooblayout_free,
 };
 
 static int denali_multidev_fixup(struct denali_nand_info *denali)