Fix another btf_type_tag issue with llvm 15

Commit 57ca51b ("Fix btf_type_tag issue with llvm 15") fixed
an issue where "btf_type_tag(rcu)" should be replaced with
"__attribute__((btf_type_tag(\"rcu\")))".

I audited some other bcc tools and found another similar failure
pattern during processing funciton arguments. Three tools are
dirtop.py, fileslower.py and filetop.py.

The failure pattern for dirtop.py looks like:

  /virtual/main.c:79:72: error: expected ')'
   struct file *file = (struct file *)ctx->di; char __user *buf =
     (char  btf_type_tag(user)*)ctx->si; size_t count = (size_t)ctx->dx;

Again, the "btf_type_tag(user)" should be replaced with
"__attribute__((btf_type_tag(\"user\")))". This patch fixed this issue.

Signed-off-by: Yonghong Song <[email protected]>

src/cc/frontends/clang/b_frontend_action.cc

@@ -787,7 +787,7 @@ void BTypeVisitor::genParamDirectAssign(FunctionDecl *D, string& preamble,
  arg->addAttr(UnavailableAttr::CreateImplicit(C, "ptregs"));
  size_t d = idx - 1;
  const char *reg = calling_conv_regs[d];
- preamble += " " + text + " = (" + arg->getType().getAsString() + ")" +
+ preamble += " " + text + " = (" + FixBTFTypeTag(arg->getType().getAsString()) + ")" +
  fn_args_[0]->getName().str() + "->" + string(reg) + ";";
  }
  }