cmd/tpm_test: Fix misleading code indentation

GCC 6.2 reasonably complains about the current code:

../cmd/tpm_test.c: In function ‘do_tpmtest’:
../cmd/tpm_test.c:540:3: warning: this ‘for’ clause does not guard... [-Wmisleading-indentation]
   for (i = 0; i < argc; i++)
   ^~~
../cmd/tpm_test.c:542:4: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the ‘for’
    printf("\n------\n");
    ^~~~~~

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Updated to remove C99 variable decl:
Signed-off-by: Simon Glass <sjg@chromium.org>