serial: amba-pl011: fix regression, causing an Oops on rmmod
serial: amba-pl011: fix regression, causing an Oops on rmmod

A recent commit ef2889f7ffee67f0aed49e854c72be63f1466759 "serial: pl011:
Move uart_register_driver call to device probe" introduced a regression,
causing the pl011 driver to Oops if more than 1 port have been probed. Fix
the Oops by only calling uart_unregister_driver() once after the last port
has been removed.

Signed-off-by: Guennadi Liakhovetski <50875182aae23d69ca7738697596f18a14e926fc@gmx.de>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs