Auto merge of #513 - yxd-hde:fix-musl, r=posborne
Auto merge of #513 - yxd-hde:fix-musl, r=posborne

Fix unresolved name error when building with musl.

See: https://git.musl-libc.org/cgit/musl/tree/src/time/timer_create.c#n126

carllerche/nix-rust,geofft/nix-rust,xd009642/nix,nix-rust/nix,berkowski/nix,berkowski/nix,posborne/rust-nix,kamalmarhubi/nix-rust,Susurrus/nix,xd009642/nix,carllerche/nix-rust,MarkusJais/nix-rust,geofft/nix-rust,geofft/nix-rust,asomers/nix,kamalmarhubi/nix-rust,MarkusJais/nix-rust,Susurrus/nix,asomers/nix,posborne/rust-nix,nix-rust/nix,xd009642/nix,kamalmarhubi/nix-rust,Susurrus/nix,berkowski/nix,carllerche/nix-rust,posborne/rust-nix,MarkusJais/nix-rust