Resolve single_match_else pedantic clippy lint

    warning: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let`
       --> src/path.rs:175:21
        |
    175 |           let qself = match qself {
        |  _____________________^
    176 | |             Some(qself) => qself,
    177 | |             None => {
    178 | |                 self.path(path, kind);
    179 | |                 return;
    180 | |             }
    181 | |         };
        | |_________^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_match_else
        = note: `-W clippy::single-match-else` implied by `-W clippy::pedantic`
        = help: to override `-W clippy::pedantic` add `#[allow(clippy::single_match_else)]`
    help: try
        |
    175 ~         let qself = if let Some(qself) = qself { qself } else {
    176 +             self.path(path, kind);
    177 +             return;
    178 ~         };
        |

src/path.rs

@@ -172,12 +172,11 @@ impl Printer {
     }
 
     pub fn qpath(&mut self, qself: &Option<QSelf>, path: &Path, kind: PathKind) {
-        let qself = match qself {
-            Some(qself) => qself,
-            None => {
-                self.path(path, kind);
-                return;
-            }
+        let qself = if let Some(qself) = qself {
+            qself
+        } else {
+            self.path(path, kind);
+            return;
         };
 
         assert!(qself.position < path.segments.len());