staging: zcache: fix zcache writeback in debugfs

commit 9c0ad59e ("zcache/debug: Use an array to initialize/use debugfs attributes")
use an array to initialize/use debugfs attributes, .name = #x, .val = &zcache_##x.
For zcache writeback, this commit set .name = zcache_outstanding_writeback_pages and
.name = zcache_writtenback_pages seperately, however, corresponding .val =
&zcache_zcache_outstanding_writeback_pages and .val = &zcache_zcache_writtenback_pages,
which are not correct.
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/zcache/debug.c

@@ -31,8 +31,8 @@ static struct debug_entry {
 	ATTR(eph_nonactive_puts_ignored),
 	ATTR(pers_nonactive_puts_ignored),
 #ifdef CONFIG_ZCACHE_WRITEBACK
-	ATTR(zcache_outstanding_writeback_pages),
-	ATTR(zcache_writtenback_pages),
+	ATTR(outstanding_writeback_pages),
+	ATTR(writtenback_pages),
 #endif
 };
 #undef ATTR