dax: fix missing-prototype warnings

dev_dax_probe declaration for this function was removed with the only
caller outside of device.c. Mark it static to avoid a W=1
warning:
drivers/dax/device.c:399:5: error: no previous prototype for 'dev_dax_probe'

Similarly, run_dax() causes a warning, but this one is because the
declaration needs to be included:

drivers/dax/super.c:337:6: error: no previous prototype for 'run_dax'

Fixes: 83762cb5c7c4 ("dax: Kill DEV_DAX_PMEM_COMPAT")
Signed-off-by: Arnd Bergmann <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Dan Williams <[e-mail]>

drivers/dax/bus.h

···
 void kill_dev_dax(struct dev_dax *dev_dax);
 bool static_dev_dax(struct dev_dax *dev_dax);
 
-/*
- * While run_dax() is potentially a generic operation that could be
- * defined in include/linux/dax.h we don't want to grow any users
- * outside of drivers/dax/
- */
-void run_dax(struct dax_device *dax_dev);
-
 #define MODULE_ALIAS_DAX_DEVICE(type) \
 	MODULE_ALIAS("dax:t" __stringify(type) "*")
 #define DAX_DEVICE_MODALIAS_FMT "dax:t%d"

drivers/dax/dax-private.h

···
 	} *ranges;
 };
 
+/*
+ * While run_dax() is potentially a generic operation that could be
+ * defined in include/linux/dax.h we don't want to grow any users
+ * outside of drivers/dax/
+ */
+void run_dax(struct dax_device *dax_dev);
+
 static inline struct dev_dax *to_dev_dax(struct device *dev)
 {
 	return container_of(dev, struct dev_dax, dev);

drivers/dax/device.c

···
 	kill_dev_dax(dev_dax);
 }
 
-int dev_dax_probe(struct dev_dax *dev_dax)
+static int dev_dax_probe(struct dev_dax *dev_dax)
 {
 	struct dax_device *dax_dev = dev_dax->dax_dev;
 	struct device *dev = &dev_dax->dev;
···
 	run_dax(dax_dev);
 	return devm_add_action_or_reset(dev, dev_dax_kill, dev_dax);
 }
-EXPORT_SYMBOL_GPL(dev_dax_probe);
 
 static struct dax_device_driver device_dax_driver = {
 	.probe = dev_dax_probe,