f2fs: delete f2fs_get_new_segment() declaration

Commit 093749e2 ("f2fs: support age threshold based garbage
collection") added this declaration, but w/ definition, delete
it.
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/f2fs.h

@@ -3700,8 +3700,6 @@ bool f2fs_segment_has_free_slot(struct f2fs_sb_info *sbi, int segno);
 void f2fs_init_inmem_curseg(struct f2fs_sb_info *sbi);
 void f2fs_save_inmem_curseg(struct f2fs_sb_info *sbi);
 void f2fs_restore_inmem_curseg(struct f2fs_sb_info *sbi);
-void f2fs_get_new_segment(struct f2fs_sb_info *sbi,
-			unsigned int *newseg, bool new_sec, int dir);
 void f2fs_allocate_segment_for_resize(struct f2fs_sb_info *sbi, int type,
 					unsigned int start, unsigned int end);
 int f2fs_allocate_new_section(struct f2fs_sb_info *sbi, int type, bool force);