CVE-2021-47363 nexthop: Fix division by zero while replacing a resilient group

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/ipv4/nexthop.c"
    ],
    "versions": [
      {
        "version": "283a72a5599e80750699d2021830a294ed9ab3f3",
        "lessThan": "e9d32ec26e7f01d1af13bdc687f586362546aa25",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "283a72a5599e80750699d2021830a294ed9ab3f3",
        "lessThan": "563f23b002534176f49524b5ca0e1d94d8906c40",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/ipv4/nexthop.c"
    ],
    "versions": [
      {
        "version": "5.13",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.13",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "5.14.9",
        "lessThanOrEqual": "5.14.*",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "5.15",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]