staging: speakup: selection: replace _manual_ swap with swap macro

Make use of the swap macro instead of _manually_ swapping values
and remove unnecessary variable tmp.

This makes the code easier to read and maintain.

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/speakup/selection.c

@@ -64,13 +64,8 @@ int speakup_set_selection(struct tty_struct *tty)
 	ps = spk_ys * vc->vc_size_row + (spk_xs << 1);
 	pe = spk_ye * vc->vc_size_row + (spk_xe << 1);
 
-	if (ps > pe) {
+	if (ps > pe)	/* make sel_start <= sel_end */
-		/* make sel_start <= sel_end */
+		swap(ps, pe);
-		int tmp = ps;
-
-		ps = pe;
-		pe = tmp;
-	}
 
 	if (spk_sel_cons != vc_cons[fg_console].d) {
 		speakup_clear_selection();