fix(kernel): fix panic handler function signature

The panic handler needs to be an extern "Rust" function not a extern "C"
function. This commit fixes that by making the panic handler a normal
function.

Signed-off-by: Anhad Singh <[email protected]>

Author: Andy-Python-Programmer

src/aero_kernel/src/unwind.rs

@@ -160,7 +160,7 @@ use crate::emu;
 use crate::utils::sync::IrqGuard;
 
 #[panic_handler]
-extern "C" fn rust_begin_unwind(info: &PanicInfo) -> ! {
+fn rust_begin_unwind(info: &PanicInfo) -> ! {
     prepare_panic();
 
     let default_panic = &format_args!("");