mmc: make __mmc_release_bus() static

This patch makes the needlessly global __mmc_release_bus() static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index b966674..ab91b02 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -516,7 +516,7 @@
 /*
  * Cleanup when the last reference to the bus operator is dropped.
  */
-void __mmc_release_bus(struct mmc_host *host)
+static void __mmc_release_bus(struct mmc_host *host)
 {
 	BUG_ON(!host);
 	BUG_ON(host->bus_refs);