Revert "Fix autoninja.bat to not swallow ^^ sequences"

This reverts commit ee3946be.

Reason for revert: This broke autoninja. The arguments all come in as one and aren't recognized. I think I can fix but I'm reverting for now.

Original change's description:
> Fix autoninja.bat to not swallow ^^ sequences
> 
> Ninja uses the '^' character to indicate that ninja should build the
> targets that are generated from the specified file, rather than
> building the specified file. On Windows '^^' is needed because '^' is
> the line continuation character. However autoninja.bat complicates
> things because the multiple levels of batch files successfully swallow
> pairs of '^' characters.
> 
> By adding quotes around %* in autoninja.bat it becomes possible to
> invoke autoninja.bat normally. That is, this works:
> 
>     autoninja -C out\debug_component ..\..\base\win\enum_variant.cc^^
> 
> It can be convenient to have a ninja.bat file which starts goma and lets
> users keep typing the same build commands. However even with this fix
> the previously recommended ninja.bat file requires four '^' characters.
> If that is too much then the new recommended ninja.bat is to copy
> autoninja.bat and modify as needed, perhaps like this:
> 
>     @echo off
>     call python c:\goma\goma-win64\goma_ctl.py ensure_start >nul
>     FOR /f "usebackq tokens=*" %%a in (`python c:\src\depot_tools\autoninja.py "%*"`) do echo %%a & %%a
> 
> BUG=758725
> 
> Change-Id: I648cf42675af2f946be7aa4033956b015d953829
> Reviewed-on: https://chromium-review.googlesource.com/651826
> Reviewed-by: Sébastien Marchand <sebmarchand@chromium.org>
> Reviewed-by: Dirk Pranke <dpranke@chromium.org>
> Commit-Queue: Bruce Dawson <brucedawson@chromium.org>

TBR=dpranke@chromium.org,brucedawson@chromium.org,sebmarchand@chromium.org

Change-Id: I131b9ba00882acb5a2d009a2a444f186740d7394
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 758725
Reviewed-on: https://chromium-review.googlesource.com/654117
Commit-Queue: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>

autoninja.bat

@@ -5,5 +5,5 @@
 
 REM Execute whatever is printed by autoninja.py.
 REM Also print it to reassure that the right settings are being used.
-FOR /f "usebackq tokens=*" %%a in (`python %~dp0autoninja.py "%*"`) do echo %%a & %%a
+FOR /f "usebackq tokens=*" %%a in (`python %~dp0autoninja.py %*`) do echo %%a & %%a