Fix Makefiles for the examples

The default rules for make were being selected before our own rules
and the .pb.c was not being built.

examples/network_server/Makefile

@@ -7,6 +7,8 @@ CFLAGS += -I$(NANOPB_DIR)
 
 all: server client
 
+.SUFFIXES:
+
 clean:
 	rm -f server client fileproto.pb.c fileproto.pb.h
 

examples/using_double_on_avr/Makefile

@@ -7,6 +7,8 @@ CFLAGS += -I$(NANOPB_DIR)
 
 all: run_tests
 
+.SUFFIXES:
+
 clean:
 	rm -f test_conversions encode_double decode_double doubleproto.pb.c doubleproto.pb.h
 

examples/using_union_messages/Makefile

@@ -10,6 +10,8 @@ all: encode decode
 	./encode 2 | ./decode
 	./encode 3 | ./decode
 
+.SUFFIXES:
+
 clean:
 	rm -f encode unionproto.pb.h unionproto.pb.c