change target binary name (remove platform name)

Index: freespace2/CMakeLists.txt
--- freespace2/CMakeLists.txt.orig
+++ freespace2/CMakeLists.txt
@@ -23,7 +23,7 @@ ADD_EXECUTABLE(Freespace2 ${EXE_GUI_TYPE} ${FREESPACE_
 
 include(resources.cmake)
 
-SET_TARGET_PROPERTIES(Freespace2 PROPERTIES OUTPUT_NAME "fs2_open_${FSO_BINARY_SUFFIX}")
+SET_TARGET_PROPERTIES(Freespace2 PROPERTIES OUTPUT_NAME "fs2open")
 
 TARGET_LINK_LIBRARIES(Freespace2 code)
 TARGET_LINK_LIBRARIES(Freespace2 platform)
