[NFC] Remove trailing whitespace in llvm/CMakeLists.txt

Differential Revision: https://reviews.llvm.org/D93234

Author: t-tye

llvm/CMakeLists.txt

@@ -378,13 +378,13 @@ option(LLVM_ENABLE_Z3_SOLVER
 
 if (LLVM_ENABLE_Z3_SOLVER)
   find_package(Z3 4.7.1)
-  
+
   if (LLVM_Z3_INSTALL_DIR)
     if (NOT Z3_FOUND)
       message(FATAL_ERROR "Z3 >= 4.7.1 has not been found in LLVM_Z3_INSTALL_DIR: ${LLVM_Z3_INSTALL_DIR}.")
     endif()
   endif()
-  
+
   if (NOT Z3_FOUND)
     message(FATAL_ERROR "LLVM_ENABLE_Z3_SOLVER cannot be enabled when Z3 is not available.")
   endif()