ext4: use the nblocks arg to ext4_truncate_restart_trans()

nblocks is passed into ext4_truncate_restart_trans() from
ext4_ext_truncate_extend_restart() with a value different from the default
blocks_for_truncate(), but is being ignored.

The two other calls to ext4_truncate_restart_trans() already pass the
default value, which is then being recalculated inside the function.

Fix the problem by using the passed argument.
Signed-off-by: Amir Goldstein <amir73il@users.sf.net>

fs/ext4/inode.c

@@ -173,7 +173,7 @@ int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode,
 	BUG_ON(EXT4_JOURNAL(inode) == NULL);
 	jbd_debug(2, "restarting handle %p\n", handle);
 	up_write(&EXT4_I(inode)->i_data_sem);
-	ret = ext4_journal_restart(handle, blocks_for_truncate(inode));
+	ret = ext4_journal_restart(handle, nblocks);
 	down_write(&EXT4_I(inode)->i_data_sem);
 	ext4_discard_preallocations(inode);