treewide: use Fatal in tests instead of Error

Error doesn't return the goroutine, but these cases are final and should end the test case.

Change-Id: I9d87e268b56acd7d1ff5883bb82bf3d74c309176
Reviewed-on: https://review.monogon.dev/c/monogon/+/4044
Reviewed-by: Jan Schär <jan@monogon.tech>
Tested-by: Jenkins CI
diff --git a/osbase/fsquota/fsquota_test.go b/osbase/fsquota/fsquota_test.go
index 97cf8bc..2850b4f 100644
--- a/osbase/fsquota/fsquota_test.go
+++ b/osbase/fsquota/fsquota_test.go
@@ -45,7 +45,7 @@
 		t.Fatal(err, string(out))
 	}
 	if err := os.Mkdir("/test", 0755); err != nil {
-		t.Error(err)
+		t.Fatal(err)
 	}
 
 	if err := unix.Mount("/dev/ram0", "/test", "xfs", unix.MS_NOEXEC|unix.MS_NODEV, "prjquota"); err != nil {