Fix NetBSD build error due to UData type mismatched (#1923)

Author: AaronChen0

Cargo.toml

@@ -47,10 +47,10 @@ net = []
 log = { version = "0.4.8", optional = true }
 
 [target.'cfg(unix)'.dependencies]
-libc = "0.2.159"
+libc = "0.2.178"
 
 [target.'cfg(target_os = "hermit")'.dependencies]
-libc = "0.2.159"
+libc = "0.2.178"
 
 [target.'cfg(windows)'.dependencies.windows-sys]
 version = "0.61"
@@ -68,7 +68,7 @@ features = [
 
 [target.'cfg(target_os = "wasi")'.dependencies]
 wasi = "0.11.0"
-libc = "0.2.159"
+libc = "0.2.178"
 
 [dev-dependencies]
 env_logger = { version = "0.11", default-features = false }

src/sys/unix/selector/kqueue.rs

@@ -50,10 +50,7 @@ type Flags = u16;
 type Flags = u32;
 
 // Type of the `udata` field in the `kevent` structure.
-#[cfg(not(target_os = "netbsd"))]
 type UData = *mut libc::c_void;
-#[cfg(target_os = "netbsd")]
-type UData = libc::intptr_t;
 
 macro_rules! kevent {
     ($id: expr, $filter: expr, $flags: expr, $data: expr) => {