Set --sandbox_tmpfs_path=/tmp for toolchain_kelvin

Change-Id: Ic0804db0a44a8999a3ac446d8f2b4cd403de9856
diff --git a/platforms/nexus/kelvin.mk b/platforms/nexus/kelvin.mk
index 7c38932..f986586 100644
--- a/platforms/nexus/kelvin.mk
+++ b/platforms/nexus/kelvin.mk
@@ -90,7 +90,8 @@
 ## Tests for Kelvin HW
 kelvin_hw_test: | $(KELVIN_HW_TESTLOG_DIR)
 	cd "$(KELVIN_HW_SRC_DIR)" && \
-		bazel test --test_output=errors //... && \
+		bazel test --test_output=errors //... \
+		--sandbox_tmpfs_path=/tmp && \
 		cp -rf bazel-testlogs/tests "$(KELVIN_HW_TESTLOG_DIR)"
 
 ## Clean Kelvin HW artifacts
diff --git a/platforms/shodan/kelvin.mk b/platforms/shodan/kelvin.mk
index 80cca4a..dc3c68e 100644
--- a/platforms/shodan/kelvin.mk
+++ b/platforms/shodan/kelvin.mk
@@ -70,7 +70,8 @@
 ## Tests for Kelvin HW
 kelvin_hw_test: | $(KELVIN_HW_TESTLOG_DIR)
 	cd "$(KELVIN_HW_SRC_DIR)" && \
-		bazel test --test_output=errors //... && \
+		bazel test --test_output=errors //... \
+		--sandbox_tmpfs_path=/tmp && \
 		cp -rf bazel-testlogs/tests "$(KELVIN_HW_TESTLOG_DIR)"
 
 ## Clean Kelvin HW artifacts