getInjections has a few lines of dead code

[lodejard]

Looks like there are some lines left over don't have a purpose after the previous change. Wouldn't cause a problem - just an extra if and a redundant return.

https://github.com/Microsoft/vscode-textmate/blob/6b4f4d7bfde2c1baaf8b25906657fd6d5075a6a3/src/grammar.ts#L384-L387