Fix soundness script (#1676)

Motivation:

The formatting script expects the '-l' flag to run the lint checker
without running the formatter. The soundness script pass 'lint' which
was ignored, so the script ran the formatter instead of the lint checker
which means the formatting checker will never fail in CI.

Modifications:

- Fix the incorrect flag
- Fix a formatting issue which crept in

Result:

CI checks formatting correctly...

Author: glbrntt

Tests/GRPCTests/InterceptedRPCCancellationTests.swift

@@ -170,10 +170,10 @@ final class MagicAddingClientInterceptor<
         interceptors: []
       )
 
-      self.retry!.invoke(onError: {
+      self.retry!.invoke {
         context.log.debug("intercepting error from retried rpc")
         context.errorCaught($0)
-      }) { responsePart in
+      } onResponsePart: { responsePart in
         context.log.debug("intercepting response part from retried rpc")
         context.receive(responsePart)
       }

scripts/sanity.sh

@@ -42,7 +42,7 @@ function check_license_headers() {
 }
 
 function check_formatting() {
-  run_logged "Checking formatting" "$HERE/format.sh lint"
+  run_logged "Checking formatting" "$HERE/format.sh -l"
 }
 
 errors=0