fix new clippy warnings

Author: syphar

Diff for: crates/font-awesome-as-a-crate/src/lib.rs

@@ -81,7 +81,7 @@ Get a fontawesome svg file by its name.
 */
 pub fn svg(type_: Type, name: &str) -> Result<&'static str, NameError> {
     let svg = fontawesome_svg(type_.as_str(), name);
-    if svg == "" {
+    if svg.is_empty() {
         return Err(NameError);
     }
     Ok(svg)

Diff for: src/web/rustdoc.rs

@@ -427,7 +427,7 @@ pub fn rustdoc_html_server_handler(req: &mut Request) -> IronResult<Response> {
         .recently_accessed_releases
         .record(krate.crate_id, krate.release_id, target);
 
-    let target = if target == "" {
+    let target = if target.is_empty() {
         String::new()
     } else {
         format!("{}/", target)