driver core: module.c: Use kasprintf

kasprintf combines kmalloc and sprintf, and takes care of the size
calculation itself.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression a,flag;
expression list args;
statement S;
@@

  a =
-  \(kmalloc\|kzalloc\)(...,flag)
+  kasprintf(flag,args)
  <... when != a
  if (a == NULL || ...) S
  ...>
- sprintf(a,args);
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/base/module.c

@@ -15,12 +15,10 @@ static char *make_driver_name(struct device_driver *drv)
 {
 	char *driver_name;
 
-	driver_name = kmalloc(strlen(drv->name) + strlen(drv->bus->name) + 2,
-			      GFP_KERNEL);
+	driver_name = kasprintf(GFP_KERNEL, "%s:%s", drv->bus->name, drv->name);
 	if (!driver_name)
 		return NULL;
 
-	sprintf(driver_name, "%s:%s", drv->bus->name, drv->name);
 	return driver_name;
 }