Remove the setting of exceptions from the pre_init example as they are now defaulted

Signed-off-by: Gabriel Smith <[email protected]>

Author: yodaldevoid

cortex-m-rt/examples/pre_init.rs

@@ -4,12 +4,10 @@
 #![no_main]
 #![no_std]
 
-#[macro_use(entry, exception, pre_init)]
+#[macro_use(entry, pre_init)]
 extern crate cortex_m_rt as rt;
 extern crate panic_semihosting;
 
-use rt::ExceptionFrame;
-
 pre_init!(disable_watchdog);
 
 unsafe fn disable_watchdog() {
@@ -22,15 +20,3 @@ entry!(main);
 fn main() -> ! {
     loop {}
 }
-
-// the hard fault handler
-exception!(HardFault, hard_fault);
-
-fn hard_fault(_ef: &ExceptionFrame) -> ! {
-    loop {}
-}
-
-// the default exception handler
-exception!(*, default_handler);
-
-fn default_handler(_irqn: i16) {}