fix(linux): executable breakes if productName given

Closes #1060

Author: stanfieldr

src/targets/fpm.ts

@@ -49,7 +49,8 @@ export default class FpmTarget extends Target {
     const packager = this.packager
     const templateOptions = Object.assign({
       // old API compatibility
-      executable: this.packager.executableName,
+      executable: packager.executableName,
+      productFilename: packager.appInfo.productFilename,
     }, packager.platformSpecificBuildOptions)
 
     function getResource(value: string | n, defaultFile: string) {
@@ -180,4 +181,4 @@ async function writeConfigFile(tmpDir: TmpDir, templatePath: string, options: an
   const outputPath = await tmpDir.getTempFile(path.basename(templatePath, ".tpl"))
   await outputFile(outputPath, config)
   return outputPath
-}
+}

templates/linux/after-install.tpl

@@ -1,4 +1,4 @@
 #!/bin/bash
 
 # Link to the binary
-ln -sf '/opt/<%= executable %>/<%= executable %>' '/usr/local/bin/<%= executable %>'
+ln -sf '/opt/<%= productFilename %>/<%= executable %>' '/usr/local/bin/<%= executable %>'