Staging: comedi: Fix checkpatch.pl issues in file s526.c

This patch fixes the following issues in s526.c:

WARNING: printk() should include KERN_ facility level
WARNING: line over 80 characters
ERROR: do not use C99 // comments
WARNING: space prohibited between function name and open parenthesis '('
WARNING: braces {} are not necessary for any arm of this statement
WARNING: suspect code indent for conditional statements (16, 16)

Signed-off-by: Xenofon Foukas <foukas.xenofon@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>