Proper string format on ValueError when MPI library is not found.

PiperOrigin-RevId: 231503050
diff --git a/configure.py b/configure.py
index adc9ef9..8dcd318 100644
--- a/configure.py
+++ b/configure.py
@@ -1482,7 +1482,7 @@
   else:
     raise ValueError(
         'Cannot find the MPI library file in %s/lib or %s/lib64 or %s/lib32' %
-        mpi_home, mpi_home, mpi_home)
+        (mpi_home, mpi_home, mpi_home))
 
 
 def set_system_libs_flag(environ_cp):