Unify errors for unsupported seccomp

To remove the message repetition we now use a global error type to avoid
the noise.

We also change the error message to point out that its not enabled by
the build, but may be enabled by the host.

Signed-off-by: Sascha Grunert <[email protected]>

seccomp_unsupported.go

@@ -7,34 +7,36 @@
 package seccomp // import "github.com/seccomp/containers-golang"
 
 import (
-	"fmt"
+	"errors"
 
 	"github.com/opencontainers/runtime-spec/specs-go"
 )
 
+var errNotSupported = errors.New("seccomp not enabled in this build")
+
 // DefaultProfile returns a nil pointer on unsupported systems.
 func DefaultProfile() *Seccomp {
 	return nil
 }
 
 // LoadProfile returns an error on unsuppored systems
 func LoadProfile(body string, rs *specs.Spec) (*specs.LinuxSeccomp, error) {
-	return nil, fmt.Errorf("Seccomp not supported on this platform")
+	return nil, errNotSupported
 }
 
 // GetDefaultProfile returns an error on unsuppored systems
 func GetDefaultProfile(rs *specs.Spec) (*specs.LinuxSeccomp, error) {
-	return nil, fmt.Errorf("Seccomp not supported on this platform")
+	return nil, errNotSupported
 }
 
 // LoadProfileFromBytes takes a byte slice and decodes the seccomp profile.
 func LoadProfileFromBytes(body []byte, rs *specs.Spec) (*specs.LinuxSeccomp, error) {
-	return nil, fmt.Errorf("Seccomp not supported on this platform")
+	return nil, errNotSupported
 }
 
 // LoadProfileFromConfig takes a Seccomp struct and a spec to retrieve a LinuxSeccomp
 func LoadProfileFromConfig(config *Seccomp, specgen *specs.Spec) (*specs.LinuxSeccomp, error) {
-	return nil, fmt.Errorf("Seccomp not supported on this platform")
+	return nil, errNotSupported
 }
 
 // IsEnabled returns true if seccomp is enabled for the host.