fusion: Add free msg frames to the head, not tail of list

Reusing a msg frame quickly means it's still cache-hot.  This yields
a small but noticable performance improvement in a well-known database
benchmark.  This improvement is already present in the mpt3sas driver.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Reviewed-by: Nicholas Bellinger <nab@linux-iscsi.org>
Reviewed-by: Praveen Krishnamoorthy <Praveen.krishnamoorthy@lsi.com>
Acked-by: Sreekanth Reddy <Sreekanth.reddy@lsi.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/message/fusion/mptbase.c

@@ -1037,7 +1037,7 @@ mpt_free_msg_frame(MPT_ADAPTER *ioc, MPT_FRAME_HDR *mf)
 		goto out;
 	/* signature to know if this mf is freed */
 	mf->u.frame.linkage.arg1 = cpu_to_le32(0xdeadbeaf);
-	list_add_tail(&mf->u.frame.linkage.list, &ioc->FreeQ);
+	list_add(&mf->u.frame.linkage.list, &ioc->FreeQ);
 #ifdef MFCNT
 	ioc->mfcnt--;
 #endif