Use the correct function name in docstring.
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index b2fee3f..bfbdf76 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -870,7 +870,7 @@
 #undef NUM_PARTIALS
 
 PyDoc_STRVAR(math_fsum_doc,
-"sum(iterable)\n\n\
+"fsum(iterable)\n\n\
 Return an accurate floating point sum of values in the iterable.\n\
 Assumes IEEE-754 floating point arithmetic.");