Fixed error message printing in write_cmake_config.py

Summary:
Previously, write_cmake_config.py would raise an error while printing
the error, because `leftovers` in "'\n'.join(leftovers)" is a tuple.

Subscribers: mgorny, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60766

llvm-svn: 358557

Author: gribozavr

llvm/utils/gn/build/write_cmake_config.py

@@ -96,7 +96,10 @@ def repl(m):
 
     leftovers = var_re.findall(output)
     if leftovers:
-        print('unprocessed values:\n', '\n'.join(leftovers), file=sys.stderr)
+        print(
+            'unprocessed values:\n',
+            '\n'.join([x[0] or x[1] for x in leftovers]),
+            file=sys.stderr)
         return 1
 
     if not os.path.exists(args.output) or open(args.output).read() != output: