pciutils: correct dns disabling logic

Fixes #8581

Commit 2c879f95a0 (pciutils: cleanup) refactored the make arguments, but
accidently changed the logic to disable dns based lookups to pass
PCIUTILS_DNS=no instead of DNS=no, causing the autotection to be used.

This autodetection looks at host includes, so it isn't safe for cross
compilation.

Disable it by setting the correct make variable instead.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/pciutils/pciutils.mk

@@ -17,7 +17,7 @@ PCIUTILS_MAKE_OPTS = \
 	LDFLAGS="$(TARGET_LDFLAGS)" \
 	RANLIB=$(TARGET_RANLIB) \
 	AR=$(TARGET_AR) \
-	PCIUTILS_DNS=no
+	DNS=no
 
 ifeq ($(BR2_PACKAGE_HAS_UDEV),y)
 PCIUTILS_DEPENDENCIES += udev