dropwatch: fix static link

Use LDLIBS for the list of libraries, since LDFLAGS appear before the source
files in the link command, and the upstream LDLIBS lacks -lncurses which is a
dependency of readline. We already pass target LDFLAGS in
TARGET_CONFIGURE_OPTS, so drop that part.

Fixes:
http://autobuild.buildroot.net/results/ce4/ce436bdd7e7950c801edac01f311b89110d87d62/
http://autobuild.buildroot.net/results/691/691d61d13849150c3616b1c74c964f50118ff1d9/
http://autobuild.buildroot.net/results/291/2918c75e473c5a2434e72f2e409becc5b4d07908/

Cc: Tzu-Jung Lee <roylee17@gmail.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/dropwatch/dropwatch.mk

@@ -11,18 +11,17 @@ DROPWATCH_LICENSE = GPL-2.0
 DROPWATCH_LICENSE_FILES = COPYING
 
 # libbfd may be linked to libintl
-# Ugly... but LDFLAGS are hardcoded anyway
-DROPWATCH_LDFLAGS = \
-	$(TARGET_LDFLAGS) -lbfd -lreadline -lnl-3 -lnl-genl-3 \
-		-lpthread -lncurses -lm
+# Ugly... but LDLIBS are hardcoded anyway
+DROPWATCH_LDLIBS = \
+	-lbfd -lreadline -lnl-3 -lnl-genl-3 -lpthread -lncurses -lm
 
 ifeq ($(BR2_NEEDS_GETTEXT_IF_LOCALE),y)
-DROPWATCH_LDFLAGS += -lintl
+DROPWATCH_LDLIBS += -lintl
 endif
 
 define DROPWATCH_BUILD_CMDS
 	$(TARGET_CONFIGURE_OPTS) $(TARGET_MAKE_ENV) $(MAKE) -C $(@D) \
-		LDFLAGS="$(DROPWATCH_LDFLAGS)" build
+		LDLIBS="$(DROPWATCH_LDLIBS)" build
 endef
 
 define DROPWATCH_INSTALL_TARGET_CMDS