[clang][docs] Inclusive language: remove use of sanity check in option description

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D114562
diff --git a/clang/docs/ThreadSafetyAnalysis.rst b/clang/docs/ThreadSafetyAnalysis.rst
index 9e18fcd..23f460b 100644
--- a/clang/docs/ThreadSafetyAnalysis.rst
+++ b/clang/docs/ThreadSafetyAnalysis.rst
@@ -466,9 +466,9 @@
 Warning flags
 -------------
 
-* ``-Wthread-safety``:  Umbrella flag which turns on the following three:
+* ``-Wthread-safety``:  Umbrella flag which turns on the following:
 
-  + ``-Wthread-safety-attributes``: Sanity checks on attribute syntax.
+  + ``-Wthread-safety-attributes``: Semantic checks for thread safety attributes.
   + ``-Wthread-safety-analysis``: The core analysis.
   + ``-Wthread-safety-precise``: Requires that mutex expressions match precisely.
        This warning can be disabled for code which has a lot of aliases.