RAS: Fix assert condition

Change-Id: Ia02a2dbfd4e25547776e78bed40a91f3452553d7
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

lib/extensions/ras/std_err_record.c

@@ -56,7 +56,7 @@ int ser_probe_sysreg(unsigned int idx_start, unsigned int num_idx, int *probe_da
 		((unsigned int) read_erridr_el1()) & ERRIDR_MASK;
 
 	assert(idx_start < max_idx);
-	assert(check_u32_overflow(idx_start, num_idx));
+	assert(check_u32_overflow(idx_start, num_idx) == 0);
 	assert((idx_start + num_idx - 1U) < max_idx);
 
 	for (i = 0; i < num_idx; i++) {