[bazel] Fix a missing comma from a2bad75

Author: d0k

utils/bazel/llvm-project-overlay/libc/BUILD.bazel

@@ -729,8 +729,8 @@ libc_support_library(
     name = "__support_fputil_manipulation_functions",
     hdrs = ["src/__support/FPUtil/ManipulationFunctions.h"],
     textual_hdrs = [
-        "src/__support/FPUtil/x86_64/NextAfterLongDouble.h"
-        "src/__support/FPUtil/x86_64/NextUpDownLongDouble.h"
+        "src/__support/FPUtil/x86_64/NextAfterLongDouble.h",
+        "src/__support/FPUtil/x86_64/NextUpDownLongDouble.h",
     ],
     deps = [
         ":__support_common",