free_full_branch(): don't bother modifying the block we are going to free

Note that it's already made unreachable from the inode, so we don't have
to worry about ufs_frag_map() walking into something already freed.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

fs/ufs/inode.c

@@ -1081,13 +1081,8 @@ static void free_full_branch(struct inode *inode, u64 ind_block, int depth)
 		for (i = 0; i < uspi->s_apb; i++) {
 			void *p = ubh_get_data_ptr(uspi, ubh, i);
 			u64 block = ufs_data_ptr_to_cpu(sb, p);
-			if (block) {
-				write_seqlock(&UFS_I(inode)->meta_lock);
-				ufs_data_ptr_clear(uspi, p);
-				write_sequnlock(&UFS_I(inode)->meta_lock);
+			if (block)
 				free_full_branch(inode, block, depth);
-				ubh_mark_buffer_dirty(ubh);
-			}
 		}
 	} else {
 		struct to_free ctx = {.inode = inode};
@@ -1095,13 +1090,8 @@ static void free_full_branch(struct inode *inode, u64 ind_block, int depth)
 		for (i = 0; i < uspi->s_apb; i++) {
 			void *p = ubh_get_data_ptr(uspi, ubh, i);
 			u64 block = ufs_data_ptr_to_cpu(sb, p);
-			if (block) {
-				write_seqlock(&UFS_I(inode)->meta_lock);
-				ufs_data_ptr_clear(uspi, p);
-				write_sequnlock(&UFS_I(inode)->meta_lock);
-				ubh_mark_buffer_dirty(ubh);
+			if (block)
 				free_data(&ctx, block, uspi->s_fpb);
-			}
 		}
 		free_data(&ctx, 0, 0);
 	}