CMake: fix MSVC Ninja build

CMakeLists.txt

@@ -138,52 +138,52 @@ include(CheckCompilerSIMDFeature)
 #
 if ("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "(x86|AMD64)")
   check_compiler_machine_option(flag SSE)
-  if (NOT ${flag} EQUAL "")
+  if (NOT ${flag} STREQUAL "")
     set(HAVE_SSE_AT_COMPILE_TIME 1)
     add_definitions(-DHAVE_SSE_AT_COMPILE_TIME)
-    if (NOT ${flag} EQUAL " ")
+    if (NOT ${flag} STREQUAL " ")
       set(GDAL_SSE_FLAG ${flag})
     endif ()
   endif ()
 
   check_compiler_machine_option(flag SSE2)
-  if (NOT ${flag} EQUAL "")
+  if (NOT ${flag} STREQUAL "")
     set(HAVE_SSE2_AT_COMPILE_TIME 1)
-    if (NOT ${flag} EQUAL " ")
+    if (NOT ${flag} STREQUAL " ")
       set(GDAL_SSE2_FLAG ${flag})
     endif ()
   endif ()
 
   check_compiler_machine_option(flag SSSE3)
-  if (NOT ${flag} EQUAL "")
+  if (NOT ${flag} STREQUAL "")
     set(HAVE_SSSE3_AT_COMPILE_TIME 1)
     add_definitions(-DHAVE_SSSE3_AT_COMPILE_TIME)
-    if (NOT ${flag} EQUAL " ")
+    if (NOT ${flag} STREQUAL " ")
       set(GDAL_SSSE3_FLAG ${flag})
     endif ()
   endif ()
 
   check_compiler_machine_option(flag SSE4_1)
-  if (NOT ${flag} EQUAL "")
+  if (NOT ${flag} STREQUAL "")
     set(HAVE_SSE41_AT_COMPILE_TIME 1)
-    if (NOT ${flag} EQUAL " ")
+    if (NOT ${flag} STREQUAL " ")
       set(GDAL_SSE41_FLAG ${flag})
     endif ()
   endif ()
 
   check_compiler_machine_option(flag AVX)
-  if (NOT ${flag} EQUAL "")
+  if (NOT ${flag} STREQUAL "")
     set(HAVE_AVX_AT_COMPILE_TIME 1)
     add_definitions(-DHAVE_AVX_AT_COMPILE_TIME)
-    if (NOT ${flag} EQUAL " ")
+    if (NOT ${flag} STREQUAL " ")
       set(GDAL_AVX_FLAG ${flag})
     endif ()
   endif ()
 
   check_compiler_machine_option(flag AVX2)
-  if (NOT ${flag} EQUAL "")
+  if (NOT ${flag} STREQUAL "")
     set(HAVE_AVX2_AT_COMPILE_TIME 1)
-    if (NOT ${flag} EQUAL " ")
+    if (NOT ${flag} STREQUAL " ")
       set(GDAL_AVX2_FLAG ${flag})
     endif ()
   endif ()