sysfs.h: fix non-kernel-doc comment

Don't use "/**" to begin this comment block since it is not a
kernel-doc comment block.

Also adjust comment line to fit in 80 characters.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>