libbpf-rs: Refine signature of Program::attach_usdt()

The Program::attach_usdt() method is generic over the USDT provider name
and the USDT name. However, given that both arguments reference the same
type parameter, they have to be of the same source type. That's an
unnecessary restriction and almost certainly not the intention.
Fix it up by making all type parameters independent of each other.

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

Author: d-e-s-o

libbpf-rs/src/program.rs

@@ -491,12 +491,12 @@ impl Program {
     /// Attach this program to a [USDT](https://lwn.net/Articles/753601/) probe
     /// point. The entry point of the program must be defined with
     /// `SEC("usdt")`.
-    pub fn attach_usdt<S: AsRef<str>, T: AsRef<Path>>(
+    pub fn attach_usdt(
         &mut self,
         pid: i32,
-        binary_path: T,
-        usdt_provider: S,
-        usdt_name: S,
+        binary_path: impl AsRef<Path>,
+        usdt_provider: impl AsRef<str>,
+        usdt_name: impl AsRef<str>,
     ) -> Result<Link> {
         let path = util::path_to_cstring(binary_path.as_ref())?;
         let path_ptr = path.as_ptr();