Fix typo in error message about sector sizes

Also remove terminating period.

Signed-off-by: mulhern <[email protected]>

src/engine/strat_engine/engine.rs

@@ -419,7 +419,7 @@ impl Engine for StratEngine {
 
             let block_size_summary = unowned_devices.blocksizes();
             if block_size_summary.len() > 1 {
-                let err_str = "The devices specified for initializing the pool do do not all have the same physical sector size or do not all have the same logical sector size.".into();
+                let err_str = "The devices specified for initializing the pool do not all have the same physical sector size or do not all have the same logical sector size".into();
                 return Err(StratisError::Msg(err_str));
             }