Fix Timeval for darwin and linux

core/os/os_darwin.odin

@@ -355,7 +355,7 @@ in6_addr :: struct #packed {
 
 Timeval :: struct {
 	seconds: i64,
-	nanoseconds: int,
+	microseconds: int,
 }
 
 Linger :: struct {

core/os/os_linux.odin

@@ -241,7 +241,7 @@ socklen_t :: c.int
 
 Timeval :: struct {
 	seconds: i64,
-	nanoseconds: int,
+	microseconds: int,
 }
 
 // "Argv" arguments converted to Odin strings
@@ -1086,4 +1086,4 @@ fcntl :: proc(fd: int, cmd: int, arg: int) -> (int, Errno) {
 		return 0, _get_errno(result)
 	}
 	return result, ERROR_NONE
-}
+}