[CMake] Fixing a typo in variable name ARG_*->LIB_*

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@252543 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/cmake/Modules/CompilerRTDarwinUtils.cmake b/cmake/Modules/CompilerRTDarwinUtils.cmake
index 2e96820..c6bfbea 100644
--- a/cmake/Modules/CompilerRTDarwinUtils.cmake
+++ b/cmake/Modules/CompilerRTDarwinUtils.cmake
@@ -186,7 +186,7 @@
     "PARENT_TARGET;OUTPUT_DIR;INSTALL_DIR"
     "LIPO_FLAGS;DEPENDS"
     ${ARGN})
-  if(ARGN_DEPENDS AND ARG_LIPO_FLAGS)
+  if(LIB_DEPENDS AND LIB_LIPO_FLAGS)
     add_custom_command(OUTPUT ${LIB_OUTPUT_DIR}/lib${name}.a
       COMMAND ${CMAKE_COMMAND} -E make_directory ${LIB_OUTPUT_DIR}
       COMMAND lipo -output