Auto merge of #5350 - matklad:simplify-install, r=djc

Simplify install

Just a mechanical simplification.

src/cargo/ops/cargo_install.rs

@@ -224,30 +224,22 @@ fn install_one(
         Some(Filesystem::new(config.cwd().join("target-install")))
     };
 
-    let ws = match overidden_target_dir {
-        Some(dir) => Workspace::ephemeral(pkg, config, Some(dir), false)?,
-        None => {
-            let mut ws = Workspace::new(pkg.manifest_path(), config)?;
-            ws.set_require_optional_deps(false);
-            ws
-        }
-    };
+    let ws = Workspace::ephemeral(pkg, config, overidden_target_dir, false)?;
     let pkg = ws.current()?;
 
     if from_cwd {
         match pkg.manifest().edition() {
-            Edition::Edition2015 =>
-                config.shell().warn("To build the current package use `cargo build`, to install the current package run `cargo install --path .`")?
-            ,
-            Edition::Edition2018 =>
-                bail!(
-                    "To build the current package use `cargo build`, \
-                     to install the current package run `cargo install --path .`, \
-                     otherwise specify a crate to install from \
-                     crates.io, or use --path or --git to \
-                     specify alternate source"
-                )
-            ,
+            Edition::Edition2015 => config.shell().warn(
+                "To build the current package use `cargo build`, \
+                 to install the current package run `cargo install --path .`",
+            )?,
+            Edition::Edition2018 => bail!(
+                "To build the current package use `cargo build`, \
+                 to install the current package run `cargo install --path .`, \
+                 otherwise specify a crate to install from \
+                 crates.io, or use --path or --git to \
+                 specify alternate source"
+            ),
         }
     };