Merge pull request #166 from brson/vs2017

Only add the 'host dylib path' to the MSVC 2017 PATH
diff --git a/src/windows_registry.rs b/src/windows_registry.rs
index 09fa940..3575809 100644
--- a/src/windows_registry.rs
+++ b/src/windows_registry.rs
@@ -218,13 +218,12 @@
 
     fn tool_from_vs15_instance(tool: &str, target: &str,
                                instance: &SetupInstance) -> Option<Tool> {
-        let (bin_path, host_bin_path, lib_path, include_path) = otry!(vs15_vc_paths(target, instance));
+        let (bin_path, host_dylib_path, lib_path, include_path) = otry!(vs15_vc_paths(target, instance));
         let tool_path = bin_path.join(tool);
         if !tool_path.exists() { return None };
 
         let mut tool = MsvcTool::new(tool_path);
-        tool.path.push(bin_path.clone());
-        tool.path.push(host_bin_path);
+        tool.path.push(host_dylib_path);
         tool.libs.push(lib_path);
         tool.include.push(include_path);
 
@@ -259,10 +258,10 @@
         // But! we also need PATH to contain the target directory for the host
         // architecture, because it contains dlls like mspdb140.dll compiled for
         // the host architecture.
-        let host_bin_path = path.join("bin").join(&format!("Host{}", host)).join(&host.to_lowercase());
+        let host_dylib_path = path.join("bin").join(&format!("Host{}", host)).join(&host.to_lowercase());
         let lib_path = path.join("lib").join(&target);
         let include_path = path.join("include");
-        Some((bin_path, host_bin_path, lib_path, include_path))
+        Some((bin_path, host_dylib_path, lib_path, include_path))
     }
 
     fn atl_paths(target: &str, path: &Path) -> Option<(PathBuf, PathBuf)> {