Avoid race conditions on profile creation

[robbrockbank]

Tom,

Just a suggested fix (I haven't tested it, although compiler looks happy enough). Just always create profile rather than check first then create.

It's one less round trip (hardly worth it perhaps), a minor simplification, but also avoids race conditions where two threads may attempt to create the profile at the same time - which you could actually just fix by checking for the ResourceAlreadyExists error on the create.

[tomdee]

Yep, much nicer code.

But

# github.com/projectcalico/libnetwork-plugin/driver
driver/network_driver.go:153: cannot use profile (type "github.com/projectcalico/libnetwork-plugin/vendor/github.com/projectcalico/libcalico-go/lib/api".Profile) as type *"github.com/projectcalico/libnetwork-plugin/vendor/github.com/projectcalico/libcalico-go/lib/api".Profile in argument to d.client.Profiles().Create
Makefile:43: recipe for target 'build' failed```

[robbrockbank]

D'oh my bad - I didn't push my fix.. It's pushed now.