Adapt for safe-isation of some libc functions.

(rust-lang/libc#1870)

Denied lint being overridden instead of unsafe block removed
to preserve compatibility with old `libc` versions.

src/sys/quota.rs

@@ -21,6 +21,7 @@ use crate::errno::Errno;
 struct QuotaCmd(QuotaSubCmd, QuotaType);
 
 impl QuotaCmd {
+    #[allow(unused_unsafe)]
     fn as_int(&self) -> c_int {
         unsafe { libc::QCMD(self.0 as i32, self.1 as i32) }
     }

src/sys/wait.rs

@@ -117,35 +117,43 @@ impl WaitStatus {
     }
 }
 
+#[allow(unused_unsafe)]
 fn exited(status: i32) -> bool {
     unsafe { libc::WIFEXITED(status) }
 }
 
+#[allow(unused_unsafe)]
 fn exit_status(status: i32) -> i32 {
     unsafe { libc::WEXITSTATUS(status) }
 }
 
+#[allow(unused_unsafe)]
 fn signaled(status: i32) -> bool {
     unsafe { libc::WIFSIGNALED(status) }
 }
 
+#[allow(unused_unsafe)]
 fn term_signal(status: i32) -> Result<Signal> {
     Signal::try_from(unsafe { libc::WTERMSIG(status) })
 }
 
+#[allow(unused_unsafe)]
 fn dumped_core(status: i32) -> bool {
     unsafe { libc::WCOREDUMP(status) }
 }
 
+#[allow(unused_unsafe)]
 fn stopped(status: i32) -> bool {
     unsafe { libc::WIFSTOPPED(status) }
 }
 
+#[allow(unused_unsafe)]
 fn stop_signal(status: i32) -> Result<Signal> {
     Signal::try_from(unsafe { libc::WSTOPSIG(status) })
 }
 
 #[cfg(any(target_os = "android", target_os = "linux"))]
+#[allow(unused_unsafe)]
 fn syscall_stop(status: i32) -> bool {
     // From ptrace(2), setting PTRACE_O_TRACESYSGOOD has the effect
     // of delivering SIGTRAP | 0x80 as the signal number for syscall
@@ -159,6 +167,7 @@ fn stop_additional(status: i32) -> c_int {
     (status >> 16) as c_int
 }
 
+#[allow(unused_unsafe)]
 fn continued(status: i32) -> bool {
     unsafe { libc::WIFCONTINUED(status) }
 }