i2c: Rename i2c_bus to I2CBus

Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
diff --git a/hw/arm/z2.c b/hw/arm/z2.c
index 97367b1..97ec381 100644
--- a/hw/arm/z2.c
+++ b/hw/arm/z2.c
@@ -308,7 +308,7 @@
     DriveInfo *dinfo;
     int be;
     void *z2_lcd;
-    i2c_bus *bus;
+    I2CBus *bus;
     DeviceState *wm;
 
     if (!cpu_model) {