Tests/BuildDepends: Drop unneeded help for Ninja

The extra post-modification invocations of 'ninja' does not seem to be
needed anymore for the BuildDepends test to pass.

Tests/BuildDepends/CMakeLists.txt

@@ -28,10 +28,6 @@ function(help_xcode_depends)
   endif()
 endfunction()
 
-if("${CMAKE_GENERATOR}" MATCHES "Ninja")
-  set(HELP_NINJA 1) # TODO Why is this needed?
-endif()
-
 # The Intel compiler causes the MSVC linker to crash during
 # incremental linking, so avoid the /INCREMENTAL:YES flag.
 if(WIN32 AND "${CMAKE_CXX_COMPILER_ID}" MATCHES "Intel")
@@ -218,7 +214,7 @@ try_compile(RESULT
   OUTPUT_VARIABLE OUTPUT)
 
 # Xcode is in serious need of help here
-if(HELP_XCODE OR HELP_NINJA)
+if(HELP_XCODE)
   try_compile(RESULT
     ${BuildDepends_BINARY_DIR}/Project
     ${BuildDepends_SOURCE_DIR}/Project