quota: Make ->set_info use structure with neccesary info to VFS and XFS

Change ->set_info to take new qc_info structure which contains all the
necessary information both for XFS and VFS. Convert Q_SETINFO handler
to use this structure.

Signed-off-by: Jan Kara <jack@suse.cz>

diff --cc fs/quota/dquot.c
Simple merge

diff --cc fs/quota/quota.c
Simple merge

diff --cc include/linux/quota.h
Simple merge

diff --cc include/linux/quotaops.h
Simple merge