Update compiler/rustc_lint/src/lifetime_style.rs

Co-authored-by: Travis Cross <[email protected]>

Author: shepmaster

compiler/rustc_lint/src/lifetime_style.rs

@@ -124,7 +124,7 @@ fn report_mismatches<'tcx>(
             // Some styles prevent using implicit syntax at all.
             let mut allow_suggesting_implicit = true;
 
-            // It only makes sense to suggest mixed if we have both sources
+            // It only makes sense to suggest mixed if we have both sources.
             let mut saw_a_reference = false;
             let mut saw_a_path = false;