Staging: comedi: dmm32at.c: Checkpatch cleanup

WARNING: braces {} are not necessary for any arm of this statement
+	if (data[0] == COMEDI_OUTPUT) {
[...]
+	} else {
[...]

Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>