ignore more tokens in some mountinfo entries (#12104)

it seems to be legitimate to have `mountinfo` lines
to have keywords with spaces such as

```
rootfs overlay / overlay rw,relatime,lowerdir...
```

This was not expected, but for our requirement
we can just ignore this and move forward.

fixes #12047

Signed-off-by: Harshavardhana <harsha@minio.io>

pkg/mountinfo/mountinfo_linux_test.go

@@ -214,7 +214,6 @@ func TestReadProcMountFrom(t *testing.T) {
 	// Error cases where parsing fails with invalid Freq and Pass params.
 	{
 		errorCases := []string{
-			"/dev/0 /path/to/mount\n",
 			"/dev/1 /path/to/mount type flags a 0\n",
 			"/dev/2 /path/to/mount type flags 0 b\n",
 		}