[Core/Debugger/FileLoaders/FileSystems/MIPS] Using reserve if possible

Core/FileSystems/ISOFileSystem.cpp

@@ -651,6 +651,7 @@ std::vector<PSPFileInfo> ISOFileSystem::GetDirListing(const std::string &path, b
 	const std::string dot(".");
 	const std::string dotdot("..");
 
+	myVector.reserve(entry->children.size() - 2);
 	for (size_t i = 0; i < entry->children.size(); i++) {
 		TreeEntry *e = entry->children[i];