Correct formatting on code listings.

The indention is coming through as non-breaking spaces in the HTML
output, which is not correct.

enforcement-case-studies.tex

@@ -334,7 +334,8 @@ file called ``README'' at the top-level directory:
 $ dd if=/dev/cdrom of=libreCMC_v1.2.1_SRC.iso
 $ mkdir libCMC
 $ sudo mount -o loop ./libreCMC_v1.2.1_SRC.iso libCMC
-  mount: block device /path/to/libreCMC_v1.2.1_SRC.iso is write-protected, mounting read-only
+mount: block device /path/to/libreCMC_v1.2.1_SRC.iso
+       is write-protected, mounting read-only
 $ ls -1 libCMC
 bin
 librecmc-u-boot.tar.bz2
@@ -342,6 +343,7 @@ file called ``README'' at the top-level directory:
 README
 u-boot_reflash
 $ cat libCMC/README
+...
 \end{lstlisting}
 \label{thinkpenguin-toplevel-readme}
 The investigator therefore knew immediately to begin the CCS check by