Check EPERM only on Linux

src/linux_android_with_fallback.rs

@@ -20,6 +20,7 @@ fn is_getrandom_available() -> bool {
     if getrandom_syscall(&[]) < 0 {
         match last_os_error().raw_os_error() {
             Some(libc::ENOSYS) => false, // No kernel support
+            #[cfg(target_os = "linux")]
             Some(libc::EPERM) => false,  // Blocked by seccomp
             _ => true,
         }