shmem: properly report quota mount options

Report quota options among the set of mount options. This allows proper
user visibility into whether quotas are enabled or not.

Link: https://lkml.kernel.org/r/20240129120131.21145-1-jack@suse.cz
Fixes: e09764cf

 ("shmem: quota support")
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>