tpm: report driver error code to upper layer

Instead of returning a generic 'library' error, report back the actual
error code so it can be displayed to the user by the regular error path.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/lib/tpm-common.c b/lib/tpm-common.c
index 33fa859..43b5308 100644
--- a/lib/tpm-common.c
+++ b/lib/tpm-common.c
@@ -169,7 +169,8 @@
 		       response, &response_length);
 
 	if (err < 0)
-		return TPM_LIB_ERROR;
+		return err;
+
 	if (size_ptr)
 		*size_ptr = response_length;