[PATCH] tpm: fix compiler error with older gcc versions

[Stefan Berger]

gcc v3.4 shows a warning due to "comparison is always false due to
limited range of data type". This patch fixes it.

Signed-off-by: Stefan Berger 
---
 src/hw/tpm_drivers.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/hw/tpm_drivers.h b/src/hw/tpm_drivers.h
index 34bb12d..48c6615 100644
--- a/src/hw/tpm_drivers.h
+++ b/src/hw/tpm_drivers.h
@@ -34,7 +34,7 @@ extern struct tpm_driver tpm_drivers[];
 #define TIS_DRIVER_IDX       0
 #define TPM_NUM_DRIVERS      1

-#define TPM_INVALID_DRIVER  -1
+#define TPM_INVALID_DRIVER   0xf

/* TIS driver */
 /* address of locality 0 (TIS) */