Coding Standards: Remove unnecessary conditional from do_trackbacks().

The check for a truthy `$to_ping` value is redundant, as a falsey value would cause the function to return early a few lines above.

Follow-up to [1794], [2612].

Props justlevine.
See #63268.

git-svn-id: https://develop.svn.wordpress.org/trunk@60406 602fd350-edb4-49c9-b593-d223f7449a82

Author: SergeyBiryukov

src/wp-includes/comment.php

@@ -3060,22 +3060,19 @@ function do_trackbacks( $post ) {
 	$post_title = apply_filters( 'the_title', $post->post_title, $post->ID );
 	$post_title = strip_tags( $post_title );
 
-	if ( $to_ping ) {
-		foreach ( (array) $to_ping as $tb_ping ) {
-			$tb_ping = trim( $tb_ping );
-			if ( ! in_array( $tb_ping, $pinged, true ) ) {
-				trackback( $tb_ping, $post_title, $excerpt, $post->ID );
-				$pinged[] = $tb_ping;
-			} else {
-				$wpdb->query(
-					$wpdb->prepare(
-						"UPDATE $wpdb->posts SET to_ping = TRIM(REPLACE(to_ping, %s,
-					'')) WHERE ID = %d",
-						$tb_ping,
-						$post->ID
-					)
-				);
-			}
+	foreach ( (array) $to_ping as $tb_ping ) {
+		$tb_ping = trim( $tb_ping );
+		if ( ! in_array( $tb_ping, $pinged, true ) ) {
+			trackback( $tb_ping, $post_title, $excerpt, $post->ID );
+			$pinged[] = $tb_ping;
+		} else {
+			$wpdb->query(
+				$wpdb->prepare(
+					"UPDATE $wpdb->posts SET to_ping = TRIM(REPLACE(to_ping, %s, '')) WHERE ID = %d",
+					$tb_ping,
+					$post->ID
+				)
+			);
 		}
 	}
 }