staging: unisys: visornic: Fix typo in visornic_main.c

This patch fix some spelling typos found in visornic_main.c

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>