USB: core: export usb_cache_string()

usb_cache_string() can also be useful for the drivers so export it.
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/all/20221130174658.29282-4-mailhol.vincent@wanadoo.frSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/usb/core/message.c

@@ -1037,6 +1037,7 @@ char *usb_cache_string(struct usb_device *udev, int index)
 	}
 	return smallbuf;
 }
+EXPORT_SYMBOL_GPL(usb_cache_string);
 
 /*
  * usb_get_device_descriptor - (re)reads the device descriptor (usbcore)

drivers/usb/core/usb.h

@@ -47,7 +47,6 @@ extern int usb_get_device_descriptor(struct usb_device *dev,
 extern int usb_set_isoch_delay(struct usb_device *dev);
 extern int usb_get_bos_descriptor(struct usb_device *dev);
 extern void usb_release_bos_descriptor(struct usb_device *dev);
-extern char *usb_cache_string(struct usb_device *udev, int index);
 extern int usb_set_configuration(struct usb_device *dev, int configuration);
 extern int usb_choose_configuration(struct usb_device *udev);
 extern int usb_generic_driver_probe(struct usb_device *udev);

include/linux/usb.h

@@ -1829,6 +1829,7 @@ static inline int usb_get_ptm_status(struct usb_device *dev, void *data)
 
 extern int usb_string(struct usb_device *dev, int index,
 	char *buf, size_t size);
+extern char *usb_cache_string(struct usb_device *udev, int index);
 
 /* wrappers that also update important state inside usbcore */
 extern int usb_clear_halt(struct usb_device *dev, int pipe);