staging: unisys: Remove unneeded spaces from channel.c

This patch removes some unneeded white space after casts within the
channel.c file.  The checkpatch script was run after these changes,
and no further checks or warnings were seen.

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