src: fix typos in node_lttng_provider.h

Is a semver-breaking change

Refs: https://github.com/nodejs/node/pull/11189#discussion_r99509433
PR-URL: https://github.com/nodejs/node/pull/11723
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

src/node_lttng_provider.h

@@ -61,7 +61,7 @@ void NODE_NET_STREAM_END(node_lttng_connection_t* conn,
 void NODE_GC_START(v8::GCType type,
                    v8::GCCallbackFlags flags,
                    v8::Isolate* isolate) {
-  const char* typeStr = "Unkown GC Type";
+  const char* typeStr = "Unknown GC Type";
   const char* flagsStr = "Unknown GC Flag";
 
 #define BUILD_IF(f) if (type == v8::GCType::f) { typeStr = #f; }
@@ -78,7 +78,7 @@ void NODE_GC_START(v8::GCType type,
 void NODE_GC_DONE(v8::GCType type,
                   v8::GCCallbackFlags flags,
                   v8::Isolate* isolate) {
-  const char* typeStr = "Unkown GC Type";
+  const char* typeStr = "Unknown GC Type";
   const char* flagsStr = "Unknown GC Flag";
 
 #define BUILD_IF(f) if (type == v8::GCType::f) { typeStr = #f; }