Fix expect on linux (#15230) (#15269)

* Fix expect on linux

* Flake8

var/spack/repos/builtin/packages/expect/package.py

@@ -66,7 +66,8 @@ def darwin_fix(self):
             fix_darwin_install_name(
                 join_path(self.prefix.lib, 'expect{0}'.format(self.version)))
 
-        old = 'libexpect{0}.dylib'.format(self.version)
-        new = glob.glob(join_path(self.prefix.lib, 'expect*', 'libexpect*'))[0]
-        install_name_tool = Executable('install_name_tool')
-        install_name_tool('-change', old, new, self.prefix.bin.expect)
+            old = 'libexpect{0}.dylib'.format(self.version)
+            new = glob.glob(join_path(self.prefix.lib, 'expect*',
+                                      'libexpect*'))[0]
+            install_name_tool = Executable('install_name_tool')
+            install_name_tool('-change', old, new, self.prefix.bin.expect)