Staging: lustre: Fix __packed is preferred over __attribute__((packed)) in libcfs_kernelcomm.h

Fix checkpatch.pl issues with  __packed is preferred over __attribute__((packed)) in libcfs_kernelcomm.h

Signed-off-by: Dilek Uzulmez <dilekuzulmez@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>