filesys/romfs: Make ProcessFile and ProcessDirectory internally linked

These functions aren't used outside of this file, so we can place them
within an anonymous namespace.

src/core/file_sys/romfs.cpp

@@ -12,7 +12,7 @@
 #include "core/file_sys/vfs_vector.h"
 
 namespace FileSys {
-
+namespace {
 constexpr u32 ROMFS_ENTRY_EMPTY = 0xFFFFFFFF;
 
 struct TableLocation {
@@ -51,7 +51,7 @@ struct FileEntry {
 static_assert(sizeof(FileEntry) == 0x20, "FileEntry has incorrect size.");
 
 template <typename Entry>
-static std::pair<Entry, std::string> GetEntry(const VirtualFile& file, std::size_t offset) {
+std::pair<Entry, std::string> GetEntry(const VirtualFile& file, std::size_t offset) {
     Entry entry{};
     if (file->ReadObject(&entry, offset) != sizeof(Entry))
         return {};
@@ -99,6 +99,7 @@ void ProcessDirectory(VirtualFile file, std::size_t dir_offset, std::size_t file
         this_dir_offset = entry.first.sibling;
     }
 }
+} // Anonymous namespace
 
 VirtualDir ExtractRomFS(VirtualFile file, RomFSExtractionType type) {
     RomFSHeader header{};