staging: unisys: Documentation: Correct a long line in doc

Correct a long line in documentation to respect the
80 character line limit.
Found using checkpatch.pl.

Signed-off-by: R Veera Kumar <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/unisys/Documentation/overview.txt

···
 * visorinput - keyboard and mouse
 
 These drivers conform to the standard Linux bus/device model described
-within Documentation/driver-api/driver-model/, and utilize a driver named visorbus to
-present the virtual busses involved. Drivers in the 'visor*' driver set are
-commonly referred to as "guest drivers" or "client drivers".  All drivers
-except visorbus expose a device of a specific usable class to the Linux guest
-environment (e.g., block, network, or input), and are collectively referred
-to as "function drivers".
+within Documentation/driver-api/driver-model/, and utilize a driver named
+visorbus to present the virtual busses involved. Drivers in the 'visor*'
+driver set are commonly referred to as "guest drivers" or "client drivers".
+All drivers except visorbus expose a device of a specific usable class to the
+Linux guest environment (e.g., block, network, or input), and are collectively
+referred to as "function drivers".
 
 The back-end for each device is owned and managed by a small,
 single-purpose service partition in the s-Par firmware, which communicates