[PATCH] CMake: bump the minimum required CMake version to 3.5

[yegorslists at googlemail.com]

From: Yegor Yefremov <yegorslists at googlemail.com>

Older CMake versions are marked as deprecated and generate
the related warning:

Compatibility with CMake < 3.5 will be removed from a future
version of CMake.

Signed-off-by: Yegor Yefremov <yegorslists at googlemail.com>
---
 CMakeLists.txt | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8e86bd4..a3eaf65 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,11 +1,9 @@
-cmake_minimum_required(VERSION 2.6)
+cmake_minimum_required(VERSION 3.5)
 
 PROJECT(netifd C)
 
-IF(NOT ${CMAKE_VERSION} LESS 3.0)
-  include(CheckCCompilerFlag)
-  check_c_compiler_flag(-Wimplicit-fallthrough HAS_IMPLICIT_FALLTHROUGH)
-ENDIF()
+include(CheckCCompilerFlag)
+check_c_compiler_flag(-Wimplicit-fallthrough HAS_IMPLICIT_FALLTHROUGH)
 
 ADD_DEFINITIONS(-Wall -Werror)
 IF(CMAKE_C_COMPILER_VERSION VERSION_GREATER 6)
-- 
2.34.1