tests: don't call testing.Testing() in mocks

With commit 6864912 ("Isolate the testing import in test code"),
the testing hooks were only ever called in binaries compiled in test
mode, meaning that checking if we are in a test doesn't really make
sense.

This is also necessary to remove because testing.Testing() was added in
Go 1.21, which is too new for some of our users.

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>

Author: cyphar

testing_mocks_linux_test.go

@@ -8,7 +8,6 @@ package securejoin
 
 import (
 	"os"
-	"testing"
 )
 
 type forceGetProcRootLevel int
@@ -33,17 +32,17 @@ func testingCheckClose(check bool, f *os.File) bool {
 }
 
 func testingForcePrivateProcRootOpenTree(f *os.File) bool {
-	return testing.Testing() && testingForceGetProcRoot != nil &&
+	return testingForceGetProcRoot != nil &&
 		testingCheckClose(*testingForceGetProcRoot >= forceGetProcRootOpenTree, f)
 }
 
 func testingForcePrivateProcRootOpenTreeAtRecursive(f *os.File) bool {
-	return testing.Testing() && testingForceGetProcRoot != nil &&
+	return testingForceGetProcRoot != nil &&
 		testingCheckClose(*testingForceGetProcRoot >= forceGetProcRootOpenTreeAtRecursive, f)
 }
 
 func testingForceGetProcRootUnsafe() bool {
-	return testing.Testing() && testingForceGetProcRoot != nil &&
+	return testingForceGetProcRoot != nil &&
 		*testingForceGetProcRoot >= forceGetProcRootUnsafe
 }
 
@@ -58,12 +57,12 @@ const (
 var testingForceProcThreadSelf *forceProcThreadSelfLevel
 
 func testingForceProcSelfTask() bool {
-	return testing.Testing() && testingForceProcThreadSelf != nil &&
+	return testingForceProcThreadSelf != nil &&
 		*testingForceProcThreadSelf >= forceProcSelfTask
 }
 
 func testingForceProcSelf() bool {
-	return testing.Testing() && testingForceProcThreadSelf != nil &&
+	return testingForceProcThreadSelf != nil &&
 		*testingForceProcThreadSelf >= forceProcSelf
 }