Unsafe block in ic-cdk storage violates code quality policy

[Andrew Lee]

• There should be an explanation of why this is safe. If unsafe, it needs an explanation of how to use it safely, and it should be marked as unsafe at the interface level.
• It should also include an explanation of why the unsafe block is necessary.

cdk-rs/src/ic-cdk/src/storage.rs

Lines 9 to 18 in 5807d2f

 fn storage() -> &'static mut StorageTree { 
     unsafe { 
         if let Some(s) = &mut STORAGE { 
             s 
         } else { 
             STORAGE = Some(BTreeMap::new()); 
             storage() 
         } 
     } 
 } 

[Adam Spofford]

Fixed in #215.