[PATCH] sysfs: handle failures in sysfs_make_dirent

I noticed that if sysfs_make_dirent fails to allocate the sd, then a
null will be passed to sysfs_put.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>