Makefile: use order-only dependency so symlinks are made only once

The rule to create the staging symlink has it depend on BASE_DIR, and
the symlink is created in BASE_DIR, which means that when the symlink
is created, BASE_DIR is updated, and thus made more recent than the
symlink itself.

As a consequence, every time one runs 'make', the symlink will be older
than BASE_DIR, and so will be re-created.

Ditto for the host symlink when the user has elected to have an
out-of-tree host dir.

Fix that by changing to using an order-only dependency.

Signed-off-by: Danomi Manchego <danomimanchego123@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit 7d38e58d4c6d62868b3973204c827b62bde4aa84)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

Makefile

@@ -457,12 +457,12 @@ endif
 
 ifneq ($(HOST_DIR),$(BASE_DIR)/host)
 HOST_DIR_SYMLINK = $(BASE_DIR)/host
-$(HOST_DIR_SYMLINK): $(BASE_DIR)
+$(HOST_DIR_SYMLINK): | $(BASE_DIR)
 	ln -snf $(HOST_DIR) $(HOST_DIR_SYMLINK)
 endif
 
 STAGING_DIR_SYMLINK = $(BASE_DIR)/staging
-$(STAGING_DIR_SYMLINK): $(BASE_DIR)
+$(STAGING_DIR_SYMLINK): | $(BASE_DIR)
 	ln -snf $(STAGING_DIR) $(STAGING_DIR_SYMLINK)
 
 # Quotes are needed for spaces and all in the original PATH content.