provide getentropy(2) instead of SYS_entropy
provide getentropy(2) instead of SYS_entropy

SYS_entropy is internal and may more easily change than getentropy(2).

cactorium/libc,superriva/libc,rust-lang-nursery/libc,rust-lang-nursery/libc,zethra/libc,cactorium/libc,zethra/libc,cactorium/libc,zethra/libc,mneumann/libc,philippkeller/libc,superriva/libc,anatol/libc,mneumann/libc,anatol/libc,philippkeller/libc,cybergeek94/libc,rust-lang/libc,mneumann/libc,anatol/libc,superriva/libc,philippkeller/libc,cybergeek94/libc,cybergeek94/libc,rust-lang/libc,rust-lang-nursery/libc,rust-lang/libc