Update CMakeLists.txt

Author: shoumikhin

extension/apple/CMakeLists.txt

@@ -70,17 +70,18 @@ file(WRITE ${MODULE_MAP_FILE}
 ")
 
 set(SWIFT_CLANG_INTEROP_FLAGS "-Xcc -fmodule-map-file=${MODULE_MAP_FILE} -I ${MODULE_MAP_DIR}")
+
 set(SWIFT_PATH_MAP_FLAGS
   "-file-prefix-map=${PROJECT_SOURCE_DIR}=/executorch"
   "-debug-prefix-map=${PROJECT_SOURCE_DIR}=/executorch"
 )
 
 set_target_properties(extension_apple PROPERTIES
   Swift_MODULE_NAME "ExecuTorch"
-  Swift_FLAGS "${SWIFT_CLANG_INTEROP_FLAGS} ${SWIFT_PATH_MAP_FLAGS}"
+  Swift_FLAGS ${SWIFT_CLANG_INTEROP_FLAGS} ${SWIFT_PATH_MAP_FLAGS}
   XCODE_ATTRIBUTE_SWIFT_MODULE_NAME "ExecuTorch"
   XCODE_ATTRIBUTE_BUILD_LIBRARY_FOR_DISTRIBUTION "YES"
-  XCODE_ATTRIBUTE_OTHER_SWIFT_FLAGS "${SWIFT_CLANG_INTEROP_FLAGS} ${SWIFT_PATH_MAP_FLAGS}"
+  XCODE_ATTRIBUTE_OTHER_SWIFT_FLAGS ${SWIFT_CLANG_INTEROP_FLAGS} ${SWIFT_PATH_MAP_FLAGS}
 )
 
 add_custom_command(