Include the associated header from vendor_dlkm_utils.cc

While writing #1850 I
ran into an issue that the compiler didn't check return type mismatches
between the same function, leading to segfaults at runtime.

Including the header makes the functions explicitly conflict.

Bug: b/464088042

Author: Databean

base/cvd/cuttlefish/host/commands/assemble_cvd/BUILD.bazel

@@ -499,6 +499,7 @@ cf_cc_library(
         "//cuttlefish/common/libs/utils:disk_usage",
         "//cuttlefish/common/libs/utils:environment",
         "//cuttlefish/common/libs/utils:files",
+        "//cuttlefish/common/libs/utils:result",
         "//cuttlefish/common/libs/utils:subprocess",
         "//cuttlefish/host/commands/assemble_cvd:boot_image_utils",
         "//cuttlefish/host/commands/assemble_cvd:kernel_module_parser",

base/cvd/cuttlefish/host/commands/assemble_cvd/vendor_dlkm_utils.cc

@@ -13,6 +13,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#include "cuttlefish/host/commands/assemble_cvd/vendor_dlkm_utils.h"
+
 #include <fcntl.h>
 
 #include <algorithm>
@@ -407,12 +409,13 @@ Result<void> RepackSuperWithPartition(const std::string& superimg_path,
   return {};
 }
 
-Result<void> BuildVbmetaImage(const std::string& image_path,
+Result<void> BuildVbmetaImage(const std::string& vendor_dlkm_img,
                               const std::string& vbmeta_path) {
-  CF_EXPECT(!image_path.empty());
-  CF_EXPECTF(FileExists(image_path), "'{}' does not exist", image_path);
+  CF_EXPECT(!vendor_dlkm_img.empty());
+  CF_EXPECTF(FileExists(vendor_dlkm_img), "'{}' does not exist",
+             vendor_dlkm_img);
 
-  CF_EXPECT(Avb().MakeVbMetaImage(vbmeta_path, {}, {image_path},
+  CF_EXPECT(Avb().MakeVbMetaImage(vbmeta_path, {}, {vendor_dlkm_img},
                                   {"--padding_size", "4096"}));
   return {};
 }

base/cvd/cuttlefish/host/commands/assemble_cvd/vendor_dlkm_utils.h

@@ -26,9 +26,6 @@ Result<void> SplitRamdiskModules(const std::string& ramdisk_path,
                                  const std::string& vendor_dlkm_build_dir,
                                  const std::string& system_dlkm_build_dir);
 
-Result<bool> WriteFsConfig(const char* output_path, const std::string& fs_root,
-                           const std::string& mount_point);
-
 Result<void> RepackSuperWithPartition(const std::string& superimg_path,
                                       const std::string& image_path,
                                       const std::string& partition_name);