Various minor warning fixes

src/JSystem/JKernel/JKRAramArchive.cpp

@@ -208,7 +208,7 @@ void* JKRAramArchive::fetchResource(SDIFileEntry* pEntry, u32* pOutSize) {
             &outBuf);
 
         *pOutSize = size;
-        if (size == NULL) {
+        if (size == 0) {
             return NULL;
         }
 
@@ -243,7 +243,7 @@ void* JKRAramArchive::fetchResource(void* buffer, u32 bufferSize, SDIFileEntry*
     } else {
         if (compression == COMPRESSION_YAZ0) {
             u32 expandSize = this->getExpandSize(pEntry);
-            if (expandSize != NULL) {
+            if (expandSize != 0) {
                 size = expandSize;
             }
         }

src/JSystem/JKernel/JKRAramStream.cpp

@@ -128,7 +128,7 @@ s32 JKRAramStream::writeToAram(JKRAramStreamCommand* command) {
         }
     }
 
-    OSSendMessage(&command->mMessageQueue, (OSMessage)writtenLength, OS_MESSAGE_NOBLOCK);
+    OSSendMessage(&command->mMessageQueue, (OSMessage)(uintptr_t)writtenLength, OS_MESSAGE_NOBLOCK);
     return writtenLength;
 }