package/nfs-utils: fix unnecessary files removal

The removal of unnecessary files is currently broken by the fact that
the rm command is executed from the buildroot directory and not the
target directory.

This patch fixes the problem changing to target directory before
removing files.

Signed-off-by: Angelo Compagnucci <angelo@amarulasolutions.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
(cherry picked from commit a64c3a847da62e56ddc5c212f0910f207f3563c4)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/nfs-utils/nfs-utils.mk

@@ -57,7 +57,7 @@ NFS_UTILS_CONF_OPTS += --disable-tirpc
 endif
 
 define NFS_UTILS_INSTALL_FIXUP
-	rm -f $(NFS_UTILS_TARGETS_)
+	cd $(TARGET_DIR) && rm -f $(NFS_UTILS_TARGETS_)
 	touch $(TARGET_DIR)/etc/exports
 	$(INSTALL) -D -m 644 \
 		$(@D)/utils/mount/nfsmount.conf $(TARGET_DIR)/etc/nfsmount.conf