3rdparty: Fix Everest platform detection for CMake
diff --git a/3rdparty/everest/CMakeLists.txt b/3rdparty/everest/CMakeLists.txt
index 5b0a078..2c5d7d5 100644
--- a/3rdparty/everest/CMakeLists.txt
+++ b/3rdparty/everest/CMakeLists.txt
@@ -11,7 +11,7 @@
     ${CMAKE_CURRENT_SOURCE_DIR}/library/kremlib/FStar_UInt64_FStar_UInt32_FStar_UInt16_FStar_UInt8.c
   )
 
-  if (${CMAKE_LIBRARY_ARCHITECTURE} STREQUAL "x86_64-linux-gnu")
+  if ("${CMAKE_LIBRARY_ARCHITECTURE}" STREQUAL "x86_64-linux-gnu")
   list(APPEND everest_src ${CMAKE_CURRENT_SOURCE_DIR}/library/Hacl_Curve25519.c)
   else()
   list(APPEND everest_def -DKRML_VERIFIED_UINT128)