mei: use correct type for counter variable in for loops

In for loops use same type for counter variable
as has the limiting variable.

drivers/misc/mei/bus-fixup.c:489:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
drivers/misc/mei/hw-txe.c:725:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
drivers/misc/mei/hw-txe.c:744:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/hw-me.c

@@ -530,9 +530,9 @@ static int mei_me_hbuf_write(struct mei_device *dev,
 {
 	unsigned long rem;
 	unsigned long length = header->length;
+	unsigned long i;
 	u32 *reg_buf = (u32 *)buf;
 	u32 dw_cnt;
-	int i;
 	int empty_slots;
 
 	dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(header));