Small fixes in documentation

typo fix + markdown fix for consistency

src/librustc_mir/interpret/eval_context.rs

@@ -98,10 +98,10 @@ pub enum StackPopCleanup {
     /// Jump to the next block in the caller, or cause UB if None (that's a function
     /// that may never return). Also store layout of return place so
     /// we can validate it at that layout.
-    /// `ret` stores the block we jump to on a normal return, while 'unwind'
-    /// stores the block used for cleanup during unwinding
+    /// `ret` stores the block we jump to on a normal return, while `unwind`
+    /// stores the block used for cleanup during unwinding.
     Goto { ret: Option<mir::BasicBlock>, unwind: Option<mir::BasicBlock> },
-    /// Just do nohing: Used by Main and for the box_alloc hook in miri.
+    /// Just do nothing: Used by Main and for the `box_alloc` hook in miri.
     /// `cleanup` says whether locals are deallocated. Static computation
     /// wants them leaked to intern what they need (and just throw away
     /// the entire `ecx` when it is done).