Do not try to update the tarball-bundled libbpf with git, which only
throws confusing errors.

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8e497e6..62ef3fc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -43,45 +39,6 @@ if(NOT NO_BLAZESYM)
   endif()
 endif()
 
-# populate submodules (libbpf)
-if(NOT CMAKE_USE_LIBBPF_PACKAGE)
-  execute_process(COMMAND git config --global --add safe.directory ${CMAKE_CURRENT_SOURCE_DIR}/src/cc/libbpf
-                  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
-                  RESULT_VARIABLE CONFIG_RESULT)
-  if(CONFIG_RESULT AND NOT CONFIG_RESULT EQUAL 0)
-    message(WARNING "Failed to add libbpf source directory to safe.directory")
-  endif()
-  execute_process(COMMAND git config --global --add safe.directory ${CMAKE_CURRENT_SOURCE_DIR}/libbpf-tools/bpftool
-                  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
-                  RESULT_VARIABLE CONFIG_RESULT)
-  if(CONFIG_RESULT AND NOT CONFIG_RESULT EQUAL 0)
-    message(WARNING "Failed to add bpftool source directory to safe.directory")
-  endif()
-
-  if(NOT EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/src/cc/libbpf/src)
-    execute_process(COMMAND git submodule update --init --recursive
-                    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
-                    RESULT_VARIABLE UPDATE_RESULT)
-    if(UPDATE_RESULT AND NOT UPDATE_RESULT EQUAL 0)
-      message(WARNING "Failed to update submodule libbpf")
-    endif()
-  else()
-    execute_process(COMMAND git diff --shortstat ${CMAKE_CURRENT_SOURCE_DIR}/src/cc/libbpf/
-                    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
-                    OUTPUT_VARIABLE DIFF_STATUS)
-    if("${DIFF_STATUS}" STREQUAL "")
-      execute_process(COMMAND git submodule update --init --recursive
-                      WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
-                      RESULT_VARIABLE UPDATE_RESULT)
-      if(UPDATE_RESULT AND NOT UPDATE_RESULT EQUAL 0)
-        message(WARNING "Failed to update submodule libbpf")
-      endif()
-    else()
-      message(WARNING "submodule libbpf dirty, so no sync")
-    endif()
-  endif()
-endif()
-
 # It's possible to use other kernel headers with
 # KERNEL_INCLUDE_DIRS build variable, like:
 #  $ cd <kernel-dir>