staging: unisys: visorbus: Fix up visordriver_probe

Fixup the visordriver_probe function. Rearrange the function to avoid
needing gotos and removed unnecessary wmb().

Signed-off-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>