Don't use TERMINFO_LIB if the library wasn't found

This actually fixes the previous commit.

Author: mstorsjo

src/CMakeLists.txt

@@ -98,7 +98,9 @@ if (NOT lib_llvm)
   endforeach()
   if (LLVM_ENABLE_TERMINFO AND NOT WIN32)
     find_library(TERMINFO_LIB NAMES terminfo tinfo curses ncurses ncursesw)
-    list(APPEND llvm_deps "${TERMINFO_LIB}")
+    if (TERMINFO_LIB)
+      list(APPEND llvm_deps "${TERMINFO_LIB}")
+    endif()
   endif()
 endif()