acpi/ghes: Change ghes fill logic to work with only one source

Extending to multiple sources require a BIOS pointer to the
beginning of the HEST table, which in turn requires a backward-compatible
code.

So, the current code supports only one source. Ensure that and simplify
the code.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <66bddd42a64c8515ad98b9975d953b4a70ffcc6d.1736945236.git.mchehab+huawei@kernel.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/acpi/ghes.c

@@ -387,15 +387,13 @@ static void get_hw_error_offsets(uint64_t ghes_addr,
      * As the current version supports only one source, the ack offset is
      * just sizeof(uint64_t).
      */
-    *read_ack_register_addr = ghes_addr +
-                              ACPI_GHES_ERROR_SOURCE_COUNT * sizeof(uint64_t);
+    *read_ack_register_addr = ghes_addr + sizeof(uint64_t);
 }
 
 void ghes_record_cper_errors(const void *cper, size_t len,
                              uint16_t source_id, Error **errp)
 {
     uint64_t cper_addr = 0, read_ack_register_addr = 0, read_ack_register;
-    uint64_t start_addr;
     AcpiGedState *acpi_ged_state;
     AcpiGhesState *ags;
 
@@ -412,11 +410,9 @@ void ghes_record_cper_errors(const void *cper, size_t len,
     }
     ags = &acpi_ged_state->ghes_state;
 
-    start_addr = le64_to_cpu(ags->hw_error_le);
-
-    start_addr += source_id * sizeof(uint64_t);
-
-    get_hw_error_offsets(start_addr, &cper_addr, &read_ack_register_addr);
+    assert(ACPI_GHES_ERROR_SOURCE_COUNT == 1);
+    get_hw_error_offsets(le64_to_cpu(ags->hw_error_le),
+                         &cper_addr, &read_ack_register_addr);
 
     if (!cper_addr) {
         error_setg(errp, "can not find Generic Error Status Block");