fuse: log options passed to fuse when mount fails

This is done to ease debugging.

Change-Id: I50cfca297e03f41cc47819d0700752e3d24a07d6
BUG: 852754
Signed-off-by: Lubomir Rintel <lubo.rintel@gooddata.com>
Reviewed-on: http://review.gluster.org/3877
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>