There is no need to keep around the debugfs "root" directory for the
dwc3 device.  Instead, look it up anytime we need to find it.  This will
help when callers get out-of-order and we had the potential to have a
"stale" pointer around for the root dentry, as has happened in the past.
Tested-by: NJack Pham <jackp@codeaurora.org>
Reviewed-by: NPeter Chen <peter.chen@kernel.org>
Acked-by: NFelipe Balbi <balbi@kernel.org>
Link: https://lore.kernel.org/r/20210609093924.3293230-1-gregkh@linuxfoundation.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>