[f2fs] code refactoring: Remove goto in GrabMetaPage (checkpoint.cc)

(comment: #16 https://fuchsia-review.googlesource.com/c/third_party/f2fs/+/520885)

Change-Id: I46fe1293fc33253b9a9d4ce7d06dbbadc0650a50
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/f2fs/+/530802
Reviewed-by: Brett Wilson <brettw@google.com>
diff --git a/checkpoint.cc b/checkpoint.cc
index 1c45967..6b9de8e 100644
--- a/checkpoint.cc
+++ b/checkpoint.cc
@@ -13,13 +13,11 @@
 
 Page *F2fs::GrabMetaPage(pgoff_t index) {
   Page *page;
-repeat:
-  page = GrabCachePage(nullptr, F2FS_META_INO(sbi_), index);
-  if (!page) {
+
+  while(!(page = GrabCachePage(nullptr, F2FS_META_INO(sbi_), index))) {
 #if 0  // porting needed
     // cond_resched();
 #endif
-    goto repeat;
   }
   /* We wait writeback only inside grab_meta_page() */
   WaitOnPageWriteback(page);