Remove pointless NIX_LOG_TYPE environment variable

doc/manual/env-common.xml

@@ -127,15 +127,6 @@ $ mount -o bind /mnt/otherdisk/nix /nix</screen>
 </varlistentry>
 
 
-<varlistentry><term><envar>NIX_LOG_TYPE</envar></term>
-
-  <listitem><para>Equivalent to the <link
-  linkend="opt-log-type"><option>--log-type</option>
-  option</link>.</para></listitem>
-
-</varlistentry>
-  
-
 <varlistentry><term><envar>TMPDIR</envar></term>
 
   <listitem><para>Use the specified directory to store temporary

src/libmain/shared.cc

@@ -144,10 +144,6 @@ static void initAndRun(int argc, char * * argv)
     gettimeofday(&tv, 0);
     srandom(tv.tv_usec);
 
-    /* Process the NIX_LOG_TYPE environment variable. */
-    string lt = getEnv("NIX_LOG_TYPE");
-    if (lt != "") setLogType(lt);
-
     /* Put the arguments in a vector. */
     Strings args, remaining;
     while (argc--) args.push_back(*argv++);