Fix typos

unkown -> unknown
fix unnecessary spacing

src/ruby/lib/grpc/errors.rb

@@ -65,7 +65,8 @@ module GRPC
       Struct::Status.new(code, details, @metadata)
     end
 
-    def self.new_status_exception(code, details = 'unkown cause', metadata = {})
+    def self.new_status_exception(code, details = 'unknown cause',
+                                  metadata = {})
       codes = {}
       codes[OK] = Ok
       codes[CANCELLED] = Cancelled

test/cpp/end2end/async_end2end_test.cc

@@ -208,7 +208,7 @@ bool plugin_has_sync_methods(std::unique_ptr<ServerBuilderPlugin>& plugin) {
 
 // This class disables the server builder plugins that may add sync services to
 // the server. If there are sync services, UnimplementedRpc test will triger
-// the sync unkown rpc routine on the server side, rather than the async one
+// the sync unknown rpc routine on the server side, rather than the async one
 // that needs to be tested here.
 class ServerBuilderSyncPluginDisabler : public ::grpc::ServerBuilderOption {
  public: