sec/intel/txt: Use 'bios_acm_error' variable

Use the variable intended for this use. This fixes building with
clang.

Change-Id: I4ee61fb9533b90ddb1a1592d5d9945761739ddb6
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63062
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/security/intel/txt/logging.c b/src/security/intel/txt/logging.c
index 46c594c..e3fcb5e 100644
--- a/src/security/intel/txt/logging.c
+++ b/src/security/intel/txt/logging.c
@@ -70,7 +70,7 @@
 	/* Errors by BIOS ACM or FIT */
 	if ((txt_error & ACMERROR_TXT_VALID) &&
 	    (acm_status & ACMERROR_TXT_VALID)) {
-		intel_txt_log_acm_error(read32((void *)TXT_BIOSACM_ERRORCODE));
+		intel_txt_log_acm_error(bios_acm_error);
 		log_txt_error("FIT MICROCODE");
 	}
 	/* Errors by SINIT */