staging: unisys: visorbus: Fix spelling error (FAIULRE to FAILURE)

There were two instances of FAILURE being misspelled in the s-Par
firmware postcode event enum that are fixed.

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