Parenthesis for Perl 5.8 - 5.22

Author: zmughal

t/file_which.t

@@ -99,7 +99,7 @@ unless (File::Which::is_vms or File::Which::is_mac or File::Which::is_win ) {
   local $ENV{PATH} = $ENV{PATH};
 
   # Where is the test application
-  my $test_bin = File::Spec->catdir( 'corpus', $^O =~ /^(MSWin32|dos|os2)$/ ? 'test-bin-win' : 'test-bin-unix' );
+  my $test_bin = File::Spec->catdir( 'corpus', ( $^O =~ /^(MSWin32|dos|os2)$/ ? 'test-bin-win' : 'test-bin-unix' ) );
   ok( -d $test_bin, 'Found test-bin' );
 
   # Set up for running the test application