[mlir] use STATUS instead of CHECK_* in MLIRDetectPythonEnv.cmake

[ftynse]

Summary

CHECK_* directives for message() where added in Cmake 3.17, LLVM
requires 3.14 as minimum so they may not be intepreted correctly and
just print "CHECK_*" into the message stream. Replace them with STATUS.

[mehdi_amini]

LGTM

mlir/cmake/modules/MLIRDetectPythonEnv.cmake

 # Macros and functions related to detecting details of the Python environment.
 
 # Detects a pybind11 package installed in the current python environment
 # and sets variables to allow it to be found. This allows pybind11 to be
 # installed via pip, which typically yields a much more recent version than
 # the OS install, which will be available otherwise.
 function(mlir_detect_pybind11_install)
   if(pybind11_DIR)
     message(STATUS "Using explicit pybind11 cmake directory: ${pybind11_DIR} (-Dpybind11_DIR to change)")
   else()
-    message(CHECK_START "Checking for pybind11 in python path...")
+    message(STATUS "Checking for pybind11 in python path...")
     execute_process(
       COMMAND "${Python3_EXECUTABLE}"
       -c "import pybind11;print(pybind11.get_cmake_dir(), end='')"
       WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
       RESULT_VARIABLE STATUS
       OUTPUT_VARIABLE PACKAGE_DIR
       ERROR_QUIET)
     if(NOT STATUS EQUAL "0")
-      message(CHECK_FAIL "not found (install via 'pip install pybind11' or set pybind11_DIR)")
+      message(STATUS "not found (install via 'pip install pybind11' or set pybind11_DIR)")
       return()
     endif()
-    message(CHECK_PASS "found (${PACKAGE_DIR})")
+    message(STATUS "found (${PACKAGE_DIR})")
     set(pybind11_DIR "${PACKAGE_DIR}" PARENT_SCOPE)
   endif()
 endfunction()