std: Improve wording of lazy_lock mod doc

Author: behnam-oneschema

library/std/src/sync/lazy_lock.rs

@@ -20,8 +20,9 @@ union Data<T, F> {
 /// A value which is initialized on the first access.
 ///
 /// This type is a thread-safe [`LazyCell`], and can be used in statics.
-/// Therefore, any dereferencing call will block the calling thread if
-/// another initialization routine is currently running.
+/// Since initialization may be called from multiple threads, any
+/// dereferencing call will block the calling thread if another
+/// initialization routine is currently running.
 ///
 /// [`LazyCell`]: crate::cell::LazyCell
 ///