fix func

Author: blink1073

.evergreen/generated_configs/functions.yml

@@ -23,7 +23,8 @@ functions:
     - command: subprocess.exec
       params:
         binary: bash
-        args: .evergreen/combine-coverage.sh
+        args:
+          - .evergreen/combine-coverage.sh
         working_dir: src
       type: test
     - command: subprocess.exec

.evergreen/scripts/generate_config.py

@@ -1249,7 +1249,7 @@ def create_download_and_merge_coverage_func():
     merge_cmd = get_subprocess_exec(
         silent=True, include_expansions_in_env=include_expansions, args=args
     )
-    combine_cmd = get_subprocess_exec(args=".evergreen/combine-coverage.sh")
+    combine_cmd = get_subprocess_exec(args=[".evergreen/combine-coverage.sh"])
     # Upload the resulting html coverage report.
     args = [
         ".evergreen/scripts/upload-coverage-report.sh",