Replace raw 'libc::syscall' with 'libc::getrandom'

Author: Aaron1011

src/linux_android.rs

@@ -15,7 +15,7 @@ pub fn getrandom_inner(dest: &mut [u8]) -> Result<(), Error> {
     static HAS_GETRANDOM: LazyBool = LazyBool::new();
     if HAS_GETRANDOM.unsync_init(is_getrandom_available) {
         sys_fill_exact(dest, |buf| unsafe {
-            libc::syscall(libc::SYS_getrandom,
+            libc::getrandom(
                           buf.as_mut_ptr() as *mut libc::c_void,
                           buf.len() as libc::size_t,
                           0 as libc::c_uint) as libc::ssize_t
@@ -26,7 +26,7 @@ pub fn getrandom_inner(dest: &mut [u8]) -> Result<(), Error> {
 }
 
 fn is_getrandom_available() -> bool {
-    let res = unsafe { libc::syscall(libc::SYS_getrandom,
+    let res = unsafe { libc::getrandom(
                                      0 as *mut libc::c_void,
                                      0 as libc::size_t,
                                      libc::GRND_NONBLOCK as libc::c_uint) };