netutils/nanopb: fix unpack step for MACOS

Currently NANOPB_UNPACK step in Makefile uses nanopb binary name with
hardcoded suffix '-linux-x86' that is not suitable for MACOS x86.
This commit replaces the hardcoded nanopb binary name with name that
is derived from NANOPB_NAME variable that reflects the nanopb binary
that is selected based on host OS selected in the build system

Signed-off-by: Petro Karashchenko <petro.karashchenko@gmail.com>

Author: pkarashchenko

netutils/nanopb/Makefile

@@ -41,7 +41,7 @@ $(NANOPB_TARBALL):
 
 $(NANOPB_UNPACK): $(NANOPB_TARBALL)
 	$(Q) tar zxf $(NANOPB_TARBALL)
-	$(Q) mv nanopb-$(NANOPB_VERSION)-linux-x86 $(NANOPB_UNPACK)
+	$(Q) mv $(NANOPB_NAME) $(NANOPB_UNPACK)
 	$(Q) mv $(NANOPB_TARBALL) $(NANOPB_UNPACK)
 
 ifeq ($(wildcard $(NANOPB_UNPACK)),)