ocfs2: Use struct ocfs2_extent_tree in ocfs2_num_free_extents().
ocfs2: Use struct ocfs2_extent_tree in ocfs2_num_free_extents().

ocfs2_num_free_extents() re-implements the logic of
ocfs2_get_extent_tree().  Now that ocfs2_get_extent_tree() does not
allocate, let's use it in ocfs2_num_free_extents() to simplify the code.

The inode validation code in ocfs2_num_free_extents() is not needed.
All callers are passing in pre-validated inodes.

Signed-off-by: Joel Becker <823d0e2e55da83c1616b20ae9a15f9456fa076e5@oracle.com>
Signed-off-by: Mark Fasheh <8f0bc92cac940f3e83deb53ced7a1f201bce5732@suse.com>

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