Address some Visual C++ compiler warnings

src/ox/fs/filestore.hpp

@@ -478,6 +478,7 @@ FsSize_t FileStore<FsSize_t>::iterator() {
 	return ptr(lastInode()) + lastInode()->size();
 }
 
+#pragma warning(disable:4244)
 template<typename FsSize_t>
 FsSize_t FileStore<FsSize_t>::ptr(void *ptr) {
 	return ((ox::std::uint8_t*) ptr) - begin();

src/ox/std/strops.cpp

@@ -34,7 +34,7 @@ int atoi(const char *str) {
 	int total = 0;
 	int multiplier = 1;
 
-	for (int i = strlen(str) - 1; i >= 0; i--) {
+	for (size_t i = strlen(str) - 1; i >= 0; i--) {
 		total += (str[i] - '0') * multiplier;
 		multiplier *= 10;
 	}