FindMPI: Place static first in mpi test source

Move the `static` added by commit 8cce0ad32f (FindMPI: Fix missing
static warning in the mpi test source, 2021-06-30, v3.22.0-rc1~502^2) to
the beginning of the line.

Fixes: #23141

Modules/FindMPI/test_mpi.c

@@ -7,7 +7,7 @@
 #endif
 
 #if defined(MPI_VERSION) && defined(MPI_SUBVERSION)
-const static char mpiver_str[] = { 'I', 'N',
+static const char mpiver_str[] = { 'I', 'N',
                                    'F', 'O',
                                    ':', 'M',
                                    'P', 'I',