ocfs2/xattr: fix credits calculation during index create
ocfs2/xattr: fix credits calculation during index create

When creating a xattr index block, the old calculation forget
to add credits for the meta change of the alloc file. So add
more credits and more comments to explain it.

Signed-off-by: Tao Ma <0490dca64807924fd58df0b0ee32b99ba7004a61@oracle.com>
Signed-off-by: Mark Fasheh <8f0bc92cac940f3e83deb53ced7a1f201bce5732@suse.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs