qapi: Fix up references to long gone error classes

Commit de253f1491 (qmp: switch to the new error format on the
wire) removed most error classes.  Several later commits mistakenly
mentioned them in documentation.  Replace them by the actual error
class there.

Fixes: 44e3e053af (qmp: add interface blockdev-snapshot-delete-internal-sync)
Fixes: f323bc9e8b (qmp: add interface blockdev-snapshot-internal-sync)
Fixes: ba1c048a8f (qapi: Introduce add-fd, remove-fd, query-fdsets)
Fixes: ed61fc10e8 (QAPI: add command for live block commit, 'block-commit')
Fixes: e4c8f004c5 (qapi: convert sendkey)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20230425064223.820979-5-armbru@redhat.com>

qapi/block-core.json

@@ -5784,7 +5784,7 @@
 #          - If any snapshot matching @name exists, or @name is empty,
 #            GenericError
 #          - If the format of the image used does not support it,
-#            BlockFormatFeatureNotSupported
+#            GenericError
 #
 # Since: 1.7
 #
@@ -5820,7 +5820,7 @@
 #          - If @device is not a valid block device, GenericError
 #          - If snapshot not found, GenericError
 #          - If the format of the image used does not support it,
-#            BlockFormatFeatureNotSupported
+#            GenericError
 #          - If @id and @name are both not specified, GenericError
 #
 # Since: 1.7

qapi/misc.json

@@ -349,8 +349,8 @@
 # @opaque: A free-form string that can be used to describe the fd.
 #
 # Returns: - @AddfdInfo on success
-#          - If file descriptor was not received, FdNotSupplied
-#          - If @fdset-id is a negative value, InvalidParameterValue
+#          - If file descriptor was not received, GenericError
+#          - If @fdset-id is a negative value, GenericError
 #
 # Notes: The list of fd sets is shared by all monitor connections.
 #
@@ -379,7 +379,7 @@
 # @fd: The file descriptor that is to be removed.
 #
 # Returns: - Nothing on success
-#          - If @fdset-id or @fd is not found, FdNotFound
+#          - If @fdset-id or @fd is not found, GenericError
 #
 # Since: 1.2
 #

qapi/ui.json

@@ -985,7 +985,7 @@
 #             to 100
 #
 # Returns: - Nothing on success
-#          - If key is unknown or redundant, InvalidParameter
+#          - If key is unknown or redundant, GenericError
 #
 # Since: 1.3
 #