Revert "Update to v5.18 kernel headers."

Revert "Update to v5.18 kernel headers."

Revert submission 2106847-kernel_update

Reason for revert: b/234125620
Reverted Changes:
I5844ca1fc:Update to v5.18 kernel headers.
I5700813ee:Update to v5.18 kernel headers.
Bug: 234125620

Change-Id: I07a39aa9c01939455b5a2a9da5fc04be497ca399
diff --git a/libc/kernel/uapi/linux/nvme_ioctl.h b/libc/kernel/uapi/linux/nvme_ioctl.h
index a2f9914..f2a328e 100644
--- a/libc/kernel/uapi/linux/nvme_ioctl.h
+++ b/libc/kernel/uapi/linux/nvme_ioctl.h
@@ -63,10 +63,7 @@
   __u64 metadata;
   __u64 addr;
   __u32 metadata_len;
-  union {
-    __u32 data_len;
-    __u32 vec_cnt;
-  };
+  __u32 data_len;
   __u32 cdw10;
   __u32 cdw11;
   __u32 cdw12;
@@ -87,5 +84,4 @@
 #define NVME_IOCTL_RESCAN _IO('N', 0x46)
 #define NVME_IOCTL_ADMIN64_CMD _IOWR('N', 0x47, struct nvme_passthru_cmd64)
 #define NVME_IOCTL_IO64_CMD _IOWR('N', 0x48, struct nvme_passthru_cmd64)
-#define NVME_IOCTL_IO64_CMD_VEC _IOWR('N', 0x49, struct nvme_passthru_cmd64)
 #endif