libc: switch `free` to the proper signature

This does not attempt to fully propagate the mutability everywhere, but
gives new code a hint to avoid the same issues.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libstd/sync/deque.rs b/src/libstd/sync/deque.rs
index e99e9ef0940..e740862fddf 100644
--- a/src/libstd/sync/deque.rs
+++ b/src/libstd/sync/deque.rs
@@ -389,7 +389,7 @@ impl<T: Send> Buffer<T> {
 impl<T: Send> Drop for Buffer<T> {
     fn drop(&mut self) {
         // It is assumed that all buffers are empty on drop.
-        unsafe { libc::free(self.storage as *libc::c_void) }
+        unsafe { libc::free(self.storage as *mut libc::c_void) }
     }
 }