[MMC] Add mmc_hostname() macro

mmc_hostname() returns a pointer to the hostname for the mmc_host.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/mmc/wbsd.c b/drivers/mmc/wbsd.c
index 974f2f3..402c2d6 100644
--- a/drivers/mmc/wbsd.c
+++ b/drivers/mmc/wbsd.c
@@ -1796,7 +1796,7 @@
 	
 	mmc_add_host(mmc);
 
-	printk(KERN_INFO "%s: W83L51xD", mmc->host_name);
+	printk(KERN_INFO "%s: W83L51xD", mmc_hostname(mmc));
 	if (host->chip_id != 0)
 		printk(" id %x", (int)host->chip_id);
 	printk(" at 0x%x irq %d", (int)host->base, (int)host->irq);