Staging: comedi: remove unnecessary else statement

Removal of an unnecessary else in statging/comedi/comedi_buf.c
Add an early Return and removed the unleashed the else condition
for better readability int staging/comedi drivers.

Signed-off-by: Swen Kalski <kalski.swen@gmail.com>
Link: https://lore.kernel.org/r/20210325133520.GA594125@m17r3en


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>