bug 1543945: geckodriver: replace str::trim_right() with ::trim_end(); r=jgraham

str::trim_right() is deprecated and has been superseded by ::trim_end().

Differential Revision: https://phabricator.services.mozilla.com/D27251

--HG--
extra : moz-landing-system : lando

testing/geckodriver/build.rs

@@ -71,7 +71,7 @@ impl Hg {
             .output()
             .ok()
             .and_then(|r| String::from_utf8(r.stdout).ok())
-            .map(|s| s.trim_right().into())
+            .map(|s| s.trim_end().into())
     }
 }
 
@@ -99,7 +99,7 @@ impl Git {
             .output()
             .ok()
             .and_then(|r| String::from_utf8(r.stdout).ok())
-            .map(|s| s.trim_right().into())
+            .map(|s| s.trim_end().into())
     }
 
     fn to_hg_sha(&self, git_sha: String) -> Option<String> {