fix: 修复FATFS中不同内部接口不支持FAT12/FAT16 FAT表结束标志

FATFS内部接口中，仅对FAT32的FAT表结束符0x0FFFFFFF做了判断，而忽略了FAT12和FAT16的结束标志。
这会导致子在FAT12/FAT16中，部分功能异常。

Close #I409R6
Signed-off-by: NFar <yesiyuan2@huawei.com>

fs/fat/os_adapt/fatfs.c

@@ -904,11 +904,13 @@ int fatfs_fallocate64(struct file *filep, int mode, off64_t offset, off64_t len)
         return -EBUSY;
     }
     result = f_expand(fp, (FSIZE_t)offset, (FSIZE_t)len, 1);
-    if (result == FR_OK && finfo->sclst == 0) {
+    if (result == FR_OK) {
+        if (finfo->sclst == 0) {
             finfo->sclst = fp->obj.sclust;
         }
         result = f_sync(fp);
-    unlock_fs(fs, FR_OK);
+    }
+    unlock_fs(fs, result);
 
     return -fatfs_2_vfs(result);
 }