[DOXYGEN] Corrected typos and incorrect parameters description.

Corrected several typos and incorrect parameters description that Sony
's techinical writer found during review.

I got an OK from Eric Christopher to commit doxygen comments without prior code
review upstream.

llvm-svn: 307838
diff --git a/clang/lib/Headers/mmintrin.h b/clang/lib/Headers/mmintrin.h
index 5a7968b..4b38d51 100644
--- a/clang/lib/Headers/mmintrin.h
+++ b/clang/lib/Headers/mmintrin.h
@@ -1289,7 +1289,7 @@
 ///
 /// \headerfile <x86intrin.h>
 ///
-/// This intrinsic corresponds to the the <c> VXORPS / XORPS </c> instruction.
+/// This intrinsic corresponds to the <c> VXORPS / XORPS </c> instruction.
 ///
 /// \returns An initialized 64-bit integer vector with all elements set to zero.
 static __inline__ __m64 __DEFAULT_FN_ATTRS