uemacs: don't forget CFLAGS at link time

Without CFLAGS, the build breaks because --sysroot is missing at link
time, and this option is absolutely mandatory for external toolchain
builds.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/uemacs/uemacs.mk

@@ -23,7 +23,7 @@ $(UEMACS_DIR)/.unpacked: $(DL_DIR)/$(UEMACS_SOURCE)
 
 $(UEMACS_DIR)/$(UEMACS_BINARY): $(UEMACS_DIR)/.unpacked
 	$(MAKE) -C $(UEMACS_DIR) \
-	CC="$(TARGET_CC)" DEFINES="-DAUTOCONF -DPOSIX -DUSG" CFLAGS+="$(TARGET_CFLAGS) " LIBS=-lncurses
+	CC="$(TARGET_CC)" DEFINES="-DAUTOCONF -DPOSIX -DUSG" CFLAGS+="$(TARGET_CFLAGS) " LIBS="$(TARGET_CFLAGS) -lncurses"
 	$(STRIPCMD) $(UEMACS_DIR)/$(UEMACS_BINARY)
 
 $(TARGET_DIR)/$(UEMACS_TARGET_BINARY): $(UEMACS_DIR)/$(UEMACS_BINARY)