Repair an incomprehensible comment.
diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c
index b576123..435c4b6 100644
--- a/Objects/obmalloc.c
+++ b/Objects/obmalloc.c
@@ -326,8 +326,8 @@
 from the pool_header to the start of "the next" virgin block is stored in
 the pool_header nextoffset member, and the largest value of nextoffset that
 makes sense is stored in the maxnextoffset member when a pool is initialized.
-All the blocks in a pool have been passed out at least when and only when
-nextoffset > maxnextoffset.
+All the blocks in a pool have been passed out at least once when and only
+when nextoffset > maxnextoffset.
 
 
 Major obscurity:  While the usedpools vector is declared to have poolp