f2fs: fix incorrect upper bound when iterating inode mapping tree

1. Inode mapping tree can index page in range of [0, ULONG_MAX], however,
in some places, f2fs only search or iterate page in ragne of [0, LONG_MAX],
result in miss hitting in page cache.

2. filemap_fdatawait_range accepts range parameters in unit of bytes, so
the max range it covers should be [0, LLONG_MAX], if we use [0, LONG_MAX]
as range for waiting on writeback, big number of pages will not be covered.

This patch corrects above two issues.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 68506f4..7b613dd 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1238,7 +1238,7 @@
 
 next_step:
 	index = 0;
-	end = LONG_MAX;
+	end = ULONG_MAX;
 
 	while (index <= end) {
 		int i, nr_pages;
@@ -1354,7 +1354,7 @@
 
 int wait_on_node_pages_writeback(struct f2fs_sb_info *sbi, nid_t ino)
 {
-	pgoff_t index = 0, end = LONG_MAX;
+	pgoff_t index = 0, end = ULONG_MAX;
 	struct pagevec pvec;
 	int ret2 = 0, ret = 0;