Drop ninja-linux32

linux32 is not supported now.

Bug: 931218
Change-Id: I753c8e1b0de5126e944d71cd7725e0ed8a4df5d8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3609948
Auto-Submit: Junji Watanabe <jwata@google.com>
Commit-Queue: Junji Watanabe <jwata@google.com>
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>

ninja

@@ -22,14 +22,10 @@ case "$OS" in
   Linux)
     MACHINE=$(uname -m)
     case "$MACHINE" in
-      i?86|x86_64)
-        LONG_BIT=$(getconf LONG_BIT)
-        # We know we are on x86 but we need to use getconf to determine
-        # bittage of the userspace install (e.g. when running 32-bit userspace
-        # on x86_64 kernel)
-        exec "${THIS_DIR}/ninja-linux${LONG_BIT}" "$@";;
+      x86_64)
+        exec "${THIS_DIR}/ninja-linux64" "$@";;
       *)
-        echo Unknown architecture \($MACHINE\) -- unable to run ninja.
+        echo Unsupported architecture \($MACHINE\) -- unable to run ninja.
         print_help
         exit 1;;
     esac