Fix cpluspluscheck for pg_verifybackup.h.

simplehash.h references pg_fatal(), which cpluspluscheck says is
undeclared, causing the CI CompilerWarnings task to fail since commit
aa2d6b1.  Include the header it needs.

Discussion: https://postgr.es/m/CA%2BhUKGJC3d4PXkErpfOWrzQqcq6MLiCv0%2BAH0CMQnB6hdLUFEw%40mail.gmail.com

src/bin/pg_verifybackup/pg_verifybackup.h

@@ -16,6 +16,7 @@
 
 #include "common/controldata_utils.h"
 #include "common/hashfn_unstable.h"
+#include "common/logging.h"
 #include "common/parse_manifest.h"
 #include "fe_utils/simple_list.h"