treewide: simplify boolean expressions

Change-Id: Ife45e57b8fdbf2a7a6fa10e00a4daf41af785996
Reviewed-on: https://review.monogon.dev/c/monogon/+/3003
Reviewed-by: Serge Bazanski <serge@monogon.tech>
Tested-by: Jenkins CI
diff --git a/metropolis/pkg/tpm/tpm.go b/metropolis/pkg/tpm/tpm.go
index f497bc6..7973399 100644
--- a/metropolis/pkg/tpm/tpm.go
+++ b/metropolis/pkg/tpm/tpm.go
@@ -187,7 +187,7 @@
 func IsInitialized() bool {
 	lock.Lock()
 	defer lock.Unlock()
-	return !(tpm == nil)
+	return tpm != nil
 }
 
 // GenerateSafeKey uses two sources of randomness (Kernel & TPM) to generate