util/nvmutil: safer / more portable install

explicitly declare the directory path for the given
file (nvmutil), otherwise it's implementation-defined;
on some systems, /bin/nvmutil means a directory named
nvmutil could then contain nvmutil.

Signed-off-by: Leah Rowe <leah@libreboot.org>

util/nvmutil/Makefile

@@ -19,7 +19,7 @@ nvmutil: nvmutil.c
 
 install:
 	mkdir -p $(DESTDIR)$(PREFIX)/bin
-	$(INSTALL) nvmutil $(DESTDIR)$(PREFIX)/bin/nvmutil
+	$(INSTALL) nvmutil $(DESTDIR)$(PREFIX)/bin/
 
 # do not delete *bin/nvm because
 # there is a package manager by