Think-o in poisson_distribution at mean == 10

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@129520 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/random b/include/random
index e08428d..49646e9 100644
--- a/include/random
+++ b/include/random
@@ -4477,7 +4477,7 @@
 {
     result_type __x;
     uniform_real_distribution<double> __urd;
-    if (__pr.__mean_ <= 10)
+    if (__pr.__mean_ < 10)
     {
          __x = 0;
         for (double __p = __urd(__urng); __p > __pr.__l_; ++__x)