usb: musb: Fix spelling mistake "tranfer" -> "transfer"

Fix spelling mistake "tranfer" -> "transfer" in musb_gadget.c file.

Signed-off-by: Saurav Girepunje <saurav.girepunje@gmail.com>
Link: https://lore.kernel.org/r/20210508072156.GA14656@user


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>