tweaks: when OR'ing, put the most likely condition first

Also, slightly reword a comment, adjust some whitespace, and use
a more direct comparison for equality.

src/utils.c

@@ -450,15 +450,15 @@ void remove_magicline(void)
 #endif
 
 #ifndef NANO_TINY
-/* Set (top, top_x) and (bot, bot_x) to the start and end "coordinates" of
- * the marked region.  If right_side_up isn't NULL, set it to TRUE when the
- * mark is at the top of the marked region, and to FALSE otherwise. */
+/* Return in (top, top_x) and (bot, bot_x) the start and end "coordinates"
+ * of the marked region.  If right_side_up isn't NULL, set it to TRUE when
+ * the mark is at the top of the marked region, and to FALSE otherwise. */
 void get_region(const linestruct **top, size_t *top_x,
-		const linestruct **bot, size_t *bot_x, bool *right_side_up)
+				const linestruct **bot, size_t *bot_x, bool *right_side_up)
 {
-	if ((openfile->current->lineno == openfile->mark->lineno &&
-				openfile->current_x > openfile->mark_x) ||
-				openfile->current->lineno > openfile->mark->lineno) {
+	if (openfile->mark->lineno < openfile->current->lineno ||
+				(openfile->mark == openfile->current &&
+				openfile->mark_x < openfile->current_x)) {
 		*top = openfile->mark;
 		*top_x = openfile->mark_x;
 		*bot = openfile->current;