Fix path error in npm installation

Author: interpretor

scripts/prebuild-install.js

@@ -1,15 +1,15 @@
 var exec = require('child_process').exec;
 
-var path = './node_modules/prebuild-install/bin.js';
+var pbi = 'prebuild-install';
 var platform = process.platform;
 var arch = process.arch;
 
 if (platform === 'linux' && arch === 'arm') {
   arch += 'v' + process.config.variables.arm_version;
-  path += ' --arch=' + arch;
+  pbi += ' --arch=' + arch;
 }
 
-exec(path, function(err, stdout, stderr) {
+exec(pbi, function(err, stdout, stderr) {
   console.log(stdout);
   console.log(stderr);
   if (err) process.exit(1);