IB/qib: Correct sense on freectxts increment and decrement

Commit 53ab1c64983 ("IB/qib: Correct nfreectxts for multiple HCAs")
reversed the increments and decrements of dd->nfreectxts.  Fix it.

Reviewed-by: Ram Vepa <ram.vepa@qlogic.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/hw/qib/qib_file_ops.c

@@ -1285,7 +1285,7 @@ static int setup_ctxt(struct qib_pportdata *ppd, int ctxt,
 	strlcpy(rcd->comm, current->comm, sizeof(rcd->comm));
 	ctxt_fp(fp) = rcd;
 	qib_stats.sps_ctxts++;
-	dd->freectxts++;
+	dd->freectxts--;
 	ret = 0;
 	goto bail;
 
@@ -1794,7 +1794,7 @@ static int qib_close(struct inode *in, struct file *fp)
 		if (dd->pageshadow)
 			unlock_expected_tids(rcd);
 		qib_stats.sps_ctxts--;
-		dd->freectxts--;
+		dd->freectxts++;
 	}
 
 	mutex_unlock(&qib_mutex);