quota: For a rename operation, do quota_check_limit only till the
common ancestor of src and dst file

Example:
set quota limit set to 1GB on /
create a file /a1/b1/file1 of 600MB
mv /a1/b1/file1 /a1/b1/file2
This rename fails as it takes delta into account which sums up to 1.2BG.
Though we are not creating new file, we still get quota exceeded error.
So quota enforce should happen only till b1.

Similarly:
mv /a/b/c/file /a/b/x/y/file
quota enforce should happen only till dir 'b'

Change-Id: Ia1e5363da876c3d71bd424e67a8bb28b7ac1c7c1
BUG: 1153964
Signed-off-by: vmallika <vmallika@redhat.com>
Reviewed-on: http://review.gluster.org/8940
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
Tested-by: Raghavendra G <rgowdapp@redhat.com>