riscv/platform/virt/devcons: remove unnecessary mut

Signed-off-by: Daniel Maslowski <info@orangecms.org>

Author: orangecms

riscv64/src/platform/virt/devcons.rs

@@ -31,7 +31,7 @@ pub fn init(dt: &DeviceTree) {
 
 pub fn init_sbi() {
     Console::new(|| {
-        let mut uart = Sbi::new();
+        let uart = Sbi::new();
 
         static mut UART: MaybeUninit<Sbi> = MaybeUninit::uninit();