[flang] fix typo in macros in __ppc_intrinsics.f90 (NFC)

Author: kkwli

flang/module/__ppc_intrinsics.f90

@@ -1293,14 +1293,14 @@ end function func_r8r8i
   end interface vsx_lxvp
   public :: vsx_lxvp
 
-#undef VEC_VP_I_VP
-#undef VEC_VP_I_VR
-#undef VEC_VP_I_VU
-#undef VEC_VP_I_VI
-#undef VP_I_VP
-#undef VP_I_VR
-#undef VP_I_VU
-#undef VP_I_VI
+#undef VEC_VP_I0_VP
+#undef VEC_VP_I0_VR
+#undef VEC_VP_I0_VU
+#undef VEC_VP_I0_VI
+#undef VP_I0_VP
+#undef VP_I0_VR
+#undef VP_I0_VU
+#undef VP_I0_VI
 
 !-----------------------------------------
 ! vector function(vector, vector, vector)