When writing the p-key setting to the ifcfg file and reading the
setting back, the value has to be consistent. This is not limited to
p-key only, any setting value during the ifcfg write and read also has
to be consistent.
This was probably added in commit cb5606cf1c ('ifcfg-rh:
add support for Infiniband partitions') as this is also what
ifup-ib does ([1]). For NetworkManager profiles however, the
p-key is also valid without the high bit set, so the ifcfg-rh
reader must honor that.
[1] 0c9fb6ca7b/rdma.ifup-ib (L75)
a4fe16a426