Improve example to not hold on to the criticial section

Signed-off-by: Daniel Egger <daniel@eggers-club.de>

examples/blinky.rs

@@ -13,25 +13,25 @@ use cortex_m_rt::entry;
 #[entry]
 fn main() -> ! {
     if let Some(mut p) = stm32::Peripherals::take() {
-        cortex_m::interrupt::free(move |cs| {
+        let mut led = cortex_m::interrupt::free(|cs| {
             let mut rcc = p.RCC.configure().sysclk(8.mhz()).freeze(&mut p.FLASH);
 
             let gpioa = p.GPIOA.split(&mut rcc);
 
             // (Re-)configure PA1 as output
-            let mut led = gpioa.pa1.into_push_pull_output(cs);
-
-            loop {
-                // Turn PA1 on a million times in a row
-                for _ in 0..1_000_000 {
-                    led.set_high();
-                }
-                // Then turn PA1 off a million times in a row
-                for _ in 0..1_000_000 {
-                    led.set_low();
-                }
-            }
+            gpioa.pa1.into_push_pull_output(cs)
         });
+
+        loop {
+            // Turn PA1 on a million times in a row
+            for _ in 0..1_000_000 {
+                led.set_high();
+            }
+            // Then turn PA1 off a million times in a row
+            for _ in 0..1_000_000 {
+                led.set_low();
+            }
+        }
     }
 
     loop {