CVE-2024-50204 fs: don't try and remove empty rbtree node

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "fs/namespace.c"
    ],
    "versions": [
      {
        "version": "1901c92497bd90caf608a474f1bf4d8795b372a2",
        "lessThan": "a8b155a2c30dc9a5ba837aa5fcba9a47cc031a9b",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1901c92497bd90caf608a474f1bf4d8795b372a2",
        "lessThan": "229fd15908fe1f99b1de4cde3326e62d1e892611",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "fs/namespace.c"
    ],
    "versions": [
      {
        "version": "6.11",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "6.11",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "6.11.6",
        "lessThanOrEqual": "6.11.*",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "6.12",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]