This was used to support QFlags f = 0 initialization, but with 0 used
as a pointer literal now considered bad form, it had been changed many
places to QFlags f = nullptr, which is meaningless and confusing.
Change-Id: I4bc592151c255dc5cab1a232615caecc520f02e8
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>