Merge pull request #2599 from ibancg/master

Problem: cannot cross-compile with Mingw-w64

CMakeLists.txt

@@ -183,7 +183,7 @@ include (CheckCXXSymbolExists)
 
 check_include_files (ifaddrs.h ZMQ_HAVE_IFADDRS)
 check_include_files (windows.h ZMQ_HAVE_WINDOWS)
-if( ${CMAKE_SYSTEM_NAME} STREQUAL "WindowsStore" AND ${CMAKE_SYSTEM_VERSION} STREQUAL "10.0")
+if(CMAKE_SYSTEM_NAME STREQUAL "WindowsStore" AND CMAKE_SYSTEM_VERSION STREQUAL "10.0")
   SET(ZMQ_HAVE_WINDOWS_UWP ON)
   ADD_DEFINITIONS(-D_WIN32_WINNT=_WIN32_WINNT_WIN10)
 endif()

tests/CMakeLists.txt

@@ -134,7 +134,7 @@ if(WIN32)
     add_definitions(-DZMQ_CUSTOM_PLATFORM_HPP)
     add_definitions(-D_WINSOCK_DEPRECATED_NO_WARNINGS)
     # Same name on 64bit systems
-    link_libraries(Ws2_32.lib)
+    link_libraries(ws2_32.lib)
 endif()
 
 # add library and include dirs for all targets