mtd: add leading underscore to all mtd functions

This patch renames all MTD functions by adding a "_" prefix:

mtd->erase -> mtd->_erase
mtd->read_oob -> mtd->_read_oob
...

The reason is that we are re-working the MTD API and from now on it is
an error to use MTD function pointers directly - we have a corresponding
API call for every pointer. By adding a leading "_" we achieve the following:

1. Make sure we convert every direct pointer users
2. A leading "_" suggests that this interface is internal and it becomes
   less likely that people will use them directly
3. Make sure all the out-of-tree modules stop compiling and the owners
   spot the big API change and amend them.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c
index 5ec5fc9..fd4a9fc 100644
--- a/drivers/mtd/devices/mtd_dataflash.c
+++ b/drivers/mtd/devices/mtd_dataflash.c
@@ -611,16 +611,16 @@
 
 static char *otp_setup(struct mtd_info *device, char revision)
 {
-	device->get_fact_prot_info = dataflash_get_otp_info;
-	device->read_fact_prot_reg = dataflash_read_fact_otp;
-	device->get_user_prot_info = dataflash_get_otp_info;
-	device->read_user_prot_reg = dataflash_read_user_otp;
+	device->_get_fact_prot_info = dataflash_get_otp_info;
+	device->_read_fact_prot_reg = dataflash_read_fact_otp;
+	device->_get_user_prot_info = dataflash_get_otp_info;
+	device->_read_user_prot_reg = dataflash_read_user_otp;
 
 	/* rev c parts (at45db321c and at45db1281 only!) use a
 	 * different write procedure; not (yet?) implemented.
 	 */
 	if (revision > 'c')
-		device->write_user_prot_reg = dataflash_write_user_otp;
+		device->_write_user_prot_reg = dataflash_write_user_otp;
 
 	return ", OTP";
 }
@@ -672,9 +672,9 @@
 	device->owner = THIS_MODULE;
 	device->type = MTD_DATAFLASH;
 	device->flags = MTD_WRITEABLE;
-	device->erase = dataflash_erase;
-	device->read = dataflash_read;
-	device->write = dataflash_write;
+	device->_erase = dataflash_erase;
+	device->_read = dataflash_read;
+	device->_write = dataflash_write;
 	device->priv = priv;
 
 	device->dev.parent = &spi->dev;