[JFFS2] Fix build failure with !CONFIG_JFFS2_FS_WRITEBUFFER

Build failure introduced by 5bf17237
[JFFS2] Write buffer offset adjustment for NOR-ECC (Sibley) flash
Signed-off-by: NSteve Glendinning <steve.glendinning@smsc.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

fs/jffs2/nodemgmt.c

@@ -261,9 +261,11 @@ static int jffs2_find_nextblock(struct jffs2_sb_info *c)
 
 	jffs2_sum_reset_collected(c->summary); /* reset collected summary */
 
+#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 	/* adjust write buffer offset, else we get a non contiguous write bug */
 	if (!(c->wbuf_ofs % c->sector_size) && !c->wbuf_len)
 		c->wbuf_ofs = 0xffffffff;
+#endif
 
 	D1(printk(KERN_DEBUG "jffs2_find_nextblock(): new nextblock = 0x%08x\n", c->nextblock->offset));