Don't download all submodules for Kokoro tests

The necessary submodules should be downloaded automatically.

Bug: b/141361933
Change-Id: Icd4690dccb851ecdc67a8f216a5727f1d8b7142a
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/43068
Presubmit-Ready: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>
diff --git a/tests/kokoro/gcp_ubuntu/continuous.sh b/tests/kokoro/gcp_ubuntu/continuous.sh
index f3a544e..d8e1aa7 100755
--- a/tests/kokoro/gcp_ubuntu/continuous.sh
+++ b/tests/kokoro/gcp_ubuntu/continuous.sh
@@ -11,9 +11,6 @@
 sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-7 100 --slave /usr/bin/g++ g++ /usr/bin/g++-7
 sudo update-alternatives --set gcc "/usr/bin/gcc-7"
 
-# Download all submodules
-git submodule update --init
-
 mkdir -p build && cd build
 
 if [[ -z "${REACTOR_BACKEND}" ]]; then
diff --git a/tests/kokoro/gcp_windows/continuous.bat b/tests/kokoro/gcp_windows/continuous.bat
index d342ada..b9195d4 100644
--- a/tests/kokoro/gcp_windows/continuous.bat
+++ b/tests/kokoro/gcp_windows/continuous.bat
@@ -14,9 +14,6 @@
   EXIT 0
 )
 
-git submodule update --init
-if !ERRORLEVEL! neq 0 exit /b !ERRORLEVEL!
-
 # Lower the amount of debug info, to reduce Kokoro build times.
 SET LESS_DEBUG_INFO=1
 
diff --git a/tests/kokoro/macos/continuous.sh b/tests/kokoro/macos/continuous.sh
index 6887369..855dfe4 100755
--- a/tests/kokoro/macos/continuous.sh
+++ b/tests/kokoro/macos/continuous.sh
@@ -7,8 +7,6 @@
 
 cd git/SwiftShader
 
-git submodule update --init
-
 mkdir -p build && cd build
 
 if [[ -z "${REACTOR_BACKEND}" ]]; then