[f2fs] code refactoring:
change unsigned long to uint64_t in f2fs.h
(comment: #142 https://fuchsia-review.googlesource.com/c/third_party/f2fs/+/511840)

Change-Id: I1c1aabb93f4faa24c2c0ca53b18bfd0831bb5886
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/f2fs/+/530784
Reviewed-by: Brett Wilson <brettw@google.com>
diff --git a/checkpoint.cc b/checkpoint.cc
index fbe0ad4..4c44b42 100644
--- a/checkpoint.cc
+++ b/checkpoint.cc
@@ -347,7 +347,7 @@
   mtx_unlock(&sbi.orphan_inode_mutex);
 }
 
-Page *F2fs::ValidateCheckpoint(block_t cp_addr, unsigned long long *version) {
+Page *F2fs::ValidateCheckpoint(block_t cp_addr, uint64_t *version) {
   Page *cp_page_1, *cp_page_2;
   unsigned long blk_size = sbi_->blocksize;
   struct f2fs_checkpoint *cp_block;
@@ -402,7 +402,7 @@
   f2fs_super_block &fsb = RawSb();
   Page *cp1, *cp2, *cur_page;
   unsigned long blk_size = sbi_->blocksize;
-  unsigned long long cp1_version = 0, cp2_version = 0;
+  uint64_t cp1_version = 0, cp2_version = 0;
   unsigned long long cp_start_blk_no;
 
   sbi_->ckpt = (f2fs_checkpoint *)malloc(blk_size);
diff --git a/f2fs.h b/f2fs.h
index 0fe854b..76c92ac 100644
--- a/f2fs.h
+++ b/f2fs.h
@@ -157,7 +157,7 @@
   int RecoverOrphanInodes();
   void WriteOrphanInodes(block_t start_blk);
   zx_status_t GetValidCheckpoint();
-  Page *ValidateCheckpoint(block_t cp_addr, unsigned long long *version);
+  Page *ValidateCheckpoint(block_t cp_addr, uint64_t *version);
 #if 0  // porting needed
   // void SetDirtyDirPage(VnodeF2fs *vnode, Page *page);
   // void RemoveDirtyDirInode(VnodeF2fs *vnode);