xfs: Add pquota fields where gquota is used.

Add project quota changes to all the places where group quota field
is used:
   * add separate project quota members into various structures
   * split project quota and group quotas so that instead of overriding
     the group quota members incore, the new project quota members are
     used instead
   * get rid of usage of the OQUOTA flag incore, in favor of separate
     group and project quota flags.
   * add a project dquot argument to various functions.

Not using the pquotino field from superblock yet.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 9560dc1f..3f90e1c 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -337,6 +337,7 @@
 		iflags |= XFS_IDONTCACHE;
 	ip->i_udquot = NULL;
 	ip->i_gdquot = NULL;
+	ip->i_pdquot = NULL;
 	xfs_iflags_set(ip, iflags);
 
 	/* insert the new inode */