Remove left behind commented #includes from fat16.cc

According to the GIT history the lines were added by this commit:
    8d808c0b
    gparted-0.3.6 - code recreation from Source Forge

Looking at the SVN history this commit actually fleshed out the
implementations of fat16::get_label() and fat32::get_label() and added
the commented #includes:
    https://sourceforge.net/p/gparted/svn/118
    Added read label support for fat16 and fat32 using mtools mlabel command
    2008-02-12

Then this SVN commit moved the mtools temporary file handling code into
Utils.cc, leaving behind the commented #includes:
    https://sourceforge.net/p/gparted/svn/124
    Added MTools temporary file handling functions
    2008-02-19

Finally this commit removed fat32.cc by merging the code with fat16.cc:
    519af1a7
    Combine duplicate code for fat16/32

So remove the left behind commented #includes from fat16.cc.
4 jobs for <span class="ref-name">online-resize-extended</span> in 77 minutes and 49 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #212461
centos_build

00:13:44

passed #212462
ubuntu_build

00:46:24

 
  Test
passed #212463
centos_test

00:09:07

passed #212464
ubuntu_test

00:31:22