Pass jshint

Ignore third party file modules/qrcode.js

Fix the few other errors:

modules/jquery.qrcode.js: line 47, col 10, Missing semicolon.
modules/jquery.qrcode.js: line 63, col 2, Mixed spaces and tabs.
modules/jquery.qrcode.js: line 81, col 10, Missing semicolon.

And clean trailing whitespaces while at it.

Bug: 61617
Change-Id: Ic462b567f1795c1fd5c4db7f7ed89b9b2d4c619e