Fix the 'make W=1' warning:
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/btrfs/btrfs.o
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>