Fix test on OpenBSD with BSD make

BSD make doesn't seem to support -C, so do not use it,
According to the documentation the working directory is set
to CMAKE_CURRENT_BINARY_DIR anyway, so it should work just the same.

Alex

Tests/FindPackageModeMakefileTest/CMakeLists.txt

@@ -15,7 +15,7 @@ if("${CMAKE_CXX_COMPILER_ID}" MATCHES GNU
     configure_file(${CMAKE_CURRENT_SOURCE_DIR}/Makefile.in ${CMAKE_CURRENT_BINARY_DIR}/ConfMakefile @ONLY)
     configure_file(${CMAKE_CURRENT_SOURCE_DIR}/main.cpp ${CMAKE_CURRENT_BINARY_DIR}/main.cpp COPYONLY)
 
-    add_test(FindPackageModeMakefileTest ${CMAKE_MAKE_PROGRAM} -f ${CMAKE_CURRENT_BINARY_DIR}/ConfMakefile -C ${CMAKE_CURRENT_BINARY_DIR} )
+    add_test(FindPackageModeMakefileTest ${CMAKE_MAKE_PROGRAM} -f ${CMAKE_CURRENT_BINARY_DIR}/ConfMakefile )
 
   endif()