infra/pkg-download: get rid of the FLOCK variable

The FLOCK variable is context-dependent, and expects the PKG
variable to be set to the current package.

This is not so nice. Besides, it is used in a single location.

Get rid of this intermediate variable, and directly use flock
where we need it.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas De Schampheleire <patrickdepinguin@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Cc: Maxime Hadjinlian <maxime.hadjinlian@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/pkg-download.mk

@@ -18,7 +18,6 @@ export SCP := $(call qstrip,$(BR2_SCP))
 export LOCALFILES := $(call qstrip,$(BR2_LOCALFILES))
 
 DL_WRAPPER = support/download/dl-wrapper
-FLOCK = flock $($(PKG)_DL_DIR)/
 
 # DL_DIR may have been set already from the environment
 ifeq ($(origin DL_DIR),undefined)
@@ -99,7 +98,7 @@ endif
 
 define DOWNLOAD
 	$(Q)mkdir -p $($(PKG)_DL_DIR)
-	$(Q)$(EXTRA_ENV) $(FLOCK) $(DL_WRAPPER) \
+	$(Q)$(EXTRA_ENV) flock $($(PKG)_DL_DIR)/ $(DL_WRAPPER) \
 		-c '$($(PKG)_DL_VERSION)' \
 		-d '$($(PKG)_DL_DIR)' \
 		-D '$(DL_DIR)' \