i965: check if upload is 0 explicitely, when downsizing a format

i965: check if upload is 0 explicitely, when downsizing a format

downsize_format_if_needed takes an integer as number of uploads
parameter. Hence, let's do an integer comparation instead of a boolean
check, since that is confusing.

Since we are at it, fix a couple of wrongly tabbed indents.

Cc: Alejandro Piñeiro <apinheiro@igalia.com>
Cc: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Andres Gomez <agomez@igalia.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>