fix elfutils (#5335)

packages/e/elfutils/xmake.lua

@@ -38,7 +38,8 @@ package("elfutils")
         on_check("android", function (package)
             local ndk = package:toolchain("ndk")
             local ndk_sdkver = ndk:config("ndk_sdkver")
-            assert(ndk and tonumber(ndk) < 26, "package(elfutils): need ndk version < 26 for android")
+            local ndkver = ndk:config("ndkver")
+            assert(ndkver and tonumber(ndkver) < 26, "package(elfutils): need ndk version < 26 for android")
             assert(ndk_sdkver and tonumber(ndk_sdkver) <= 23, "package(elfutils): need ndk api level <= 23 for android")
         end)
     end