fixed 64d15df from https://gitee.com/yesiyuanjim/kernel_liteos_m/pulls/909

fix: fix the MS_REMOUNT support

The mount interface can't deal with MS_REMOUNT flag now, fix it.

Signed-off-by: Far <yesiyuan2@huawei.com>
Change-Id: Id0960c8d92ce767b8d8ef98b3ba2e1d1ab7db15d

components/fs/fatfs/fatfs.c

@@ -282,6 +282,12 @@ int FatfsMount(struct MountPoint *mp, unsigned long mountflags,
         return (int)LOS_NOK;
     }
 
+    if (mountflags & MS_REMOUNT) {
+        ret = Remount(mp, mountflags);
+        FsUnlock();
+        return ret;
+    }
+
     char *ldPath = GetLdPath(mp->mDev);
     if (ldPath == NULL) {
         errno = EFAULT;
@@ -289,11 +295,6 @@ int FatfsMount(struct MountPoint *mp, unsigned long mountflags,
         goto ERROUT;
     }
 
-    if (mountflags & MS_REMOUNT) {
-        ret = Remount(mp, mountflags);
-        goto ERROUT;
-    }
-
     fs = (FATFS *)malloc(sizeof(FATFS));
     if (fs == NULL) {
         errno = ENOMEM;