Add missing PVS Studio Open Source comments.

Also avoid checking protobuf-c source and protobuf-c generated files.

lib/util/Makefile.in

@@ -197,11 +197,6 @@ FUZZ_SUDO_CONF_CORPUS = $(srcdir)/regress/corpus/seed/sudo_conf/sudo.conf.*
 
 all: libsudo_util.la
 
-pvs-log-files: $(POBJS)
-
-pvs-studio: $(POBJS)
-	plog-converter $(PVS_LOG_OPTS) $(POBJS)
-
 depend: siglist.c signame.c
 	$(scriptdir)/mkdep.pl --srcdir=$(abs_top_srcdir) \
 	    --builddir=$(abs_top_builddir) lib/util/Makefile.in
@@ -395,6 +390,9 @@ cppcheck:
 
 pvs-log-files: $(POBJS)
 
+pvs-studio: $(POBJS)
+	plog-converter $(PVS_LOG_OPTS) $(POBJS)
+
 fuzz: run-fuzz_sudo_conf
 
 check-fuzzer: $(FUZZ_PROGS)

lib/util/getentropy.c

@@ -20,6 +20,11 @@
  * http://man.openbsd.org/getentropy.2
  */
 
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
 #include <config.h>
 
 #ifndef HAVE_GETENTROPY

lib/util/roundup.c

@@ -16,6 +16,11 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
 #include <config.h>
 
 #include "sudo_compat.h"