Add a comment in bios-tables-test.c to clarify the reason behind approach

A comment is added in bios-tables-test.c that explains the reasoning
behind the process of updating the ACPI table blobs when new tests are added
or old tests are modified or code is committed that affect tests. The
explanation would help future contributors follow the correct process when
making code changes that affect ACPI tables.

Signed-off-by: Ani Sinha <ani@anisinha.ca>
Acked-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20200929142501.1057-1-ani@anisinha.ca>
Signed-off-by: Thomas Huth <thuth@redhat.com>

tests/qtest/bios-tables-test.c

@@ -11,7 +11,7 @@
  */
 
 /*
- * How to add or update the tests:
+ * How to add or update the tests or commit changes that affect ACPI tables:
  * Contributor:
  * 1. add empty files for new tables, if any, under tests/data/acpi
  * 2. list any changed files in tests/qtest/bios-tables-test-allowed-diff.h
@@ -38,6 +38,11 @@
  *      $(SRC_PATH)/tests/data/acpi/rebuild-expected-aml.sh
  * 6. Now commit any changes to the expected binary, include diff from step 4
  *    in commit log.
+ *    Expected binary updates needs to be a separate patch from the code that
+ *    introduces changes to ACPI tables. It lets the maintainer drop
+ *    and regenerate binary updates in case of merge conflicts. Further, a code
+ *    change is easily reviewable but a binary blob is not (without doing a
+ *    disassembly).
  * 7. Before sending patches to the list (Contributor)
  *    or before doing a pull request (Maintainer), make sure
  *    tests/qtest/bios-tables-test-allowed-diff.h is empty - this will ensure