libbpf-cargo: Remove unnecessary 'clang' setting

Usage of clang as the compiler is the default for the SkeletonBuilder
type. Hence, there is no need to instruct it to use this compiler
explicitly.

Signed-off-by: Daniel Müller <deso@posteo.net>

libbpf-cargo/src/test.rs

@@ -423,7 +423,7 @@ fn build_rust_project_from_bpf_c_impl(bpf_c: &str, rust: &str, run: bool) {
         .arg(cargo_toml.into_os_string())
         .env("RUSTFLAGS", "-Dwarnings")
         .status()
-        .expect("failed to spawn cargo-build");
+        .expect("failed to run cargo");
     assert!(status.success());
 }
 
@@ -774,14 +774,12 @@ fn test_skeleton_builder_clang_opts() {
     // Should fail b/c `PURPOSE` not defined
     SkeletonBuilder::new()
         .source(proj_dir.join("src/bpf/prog.bpf.c"))
-        .clang("clang")
         .build_and_generate(skel.path())
         .unwrap_err();
 
     // Should succeed b/c we defined the macro
     SkeletonBuilder::new()
         .source(proj_dir.join("src/bpf/prog.bpf.c"))
-        .clang("clang")
         .clang_args(["-DPURPOSE=you_pass_the_butter"])
         .build_and_generate(skel.path())
         .unwrap();
@@ -1086,15 +1084,13 @@ fn test_skeleton_builder_deterministic() {
     let skel1 = NamedTempFile::new().unwrap();
     SkeletonBuilder::new()
         .source(proj_dir.join("src/bpf/prog.bpf.c"))
-        .clang("clang")
         .build_and_generate(skel1.path())
         .unwrap();
     let skel1 = read_to_string(skel1.path()).unwrap();
 
     let skel2 = NamedTempFile::new().unwrap();
     SkeletonBuilder::new()
         .source(proj_dir.join("src/bpf/prog.bpf.c"))
-        .clang("clang")
         .build_and_generate(skel2.path())
         .unwrap();
     let skel2 = read_to_string(skel2.path()).unwrap();