Update unsafe comments

Author: qwerty19106

src/peripheral/scb.rs

@@ -950,8 +950,7 @@ impl SCB {
         {
             // NOTE(unsafe) atomic read with no side effects
 
-            // NOTE(unsafe): prevent unnecessary bounds check! Index of shpr array is
-            // true by SystemHandler design.
+            // NOTE(unsafe): Index is bounded to [4,15] by SystemHandler design.
             let priority_ref = unsafe {(*Self::ptr()).shpr.get_unchecked(usize::from(index - 4))};
 
             priority_ref.read()
@@ -961,8 +960,7 @@ impl SCB {
         {
             // NOTE(unsafe) atomic read with no side effects
 
-            // NOTE(unsafe): prevent unnecessary bounds check! Index of shpr array is
-            // true by SystemHandler design.
+            // NOTE(unsafe): Index is bounded to [11,15] by SystemHandler design.
             let priority_ref = unsafe {(*Self::ptr()).shpr.get_unchecked(usize::from((index - 8) / 4))};
 
             let shpr = priority_ref.read();
@@ -989,17 +987,15 @@ impl SCB {
 
         #[cfg(not(armv6m))]
         {
-            // NOTE(unsafe): prevent unnecessary bounds check! Index of shpr array is
-            // true by SystemHandler design.
+            // NOTE(unsafe): Index is bounded to [4,15] by SystemHandler design.
             let priority_ref = (*Self::ptr()).shpr.get_unchecked(usize::from(index - 4));
 
             priority_ref.write(prio)
         }
 
         #[cfg(armv6m)]
         {
-            // NOTE(unsafe): prevent unnecessary bounds check! Index of shpr array is
-            // true by SystemHandler design.
+            // NOTE(unsafe): Index is bounded to [11,15] by SystemHandler design.
             let priority_ref = (*Self::ptr()).shpr.get_unchecked(usize::from((index - 8) / 4));
 
             priority_ref.modify(|value| {