staging: unisys: Fix "else not useful after return" warning in virthba.c

This patch fixes a warning generated during the checkpatch script that stated
"else not useful after return".  I modified the code to return a designated
status at the end of the function, and replaced the return statement in the
"else if" to set the status accordingly.

Signed-off-by: Ken Depro <kenneth.depro@unisys.com>
Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>