Remove O_FSYNC, musl don't define it. Use O_SYNC instead.

Author: 12101111

src/unix/linux_like/linux/musl/b32/riscv32/mod.rs

@@ -124,7 +124,6 @@ pub const O_NONBLOCK: c_int = 2048;
 pub const O_SYNC: c_int = 1052672;
 pub const O_RSYNC: c_int = 1052672;
 pub const O_DSYNC: c_int = 4096;
-pub const O_FSYNC: c_int = 1052672;
 pub const MAP_GROWSDOWN: c_int = 256;
 pub const EDEADLK: c_int = 35;
 pub const ENAMETOOLONG: c_int = 36;