package/elixir: fix host-erlang dependency

There is no target elixir package, so setting a value to
ELIXIR_DEPENDENCIES has no effect, HOST_ELIXIR_DEPENDENCIES must be
used instead.

Fixes:

  http://autobuild.buildroot.net/results/a3a37eb724ca5689f8e83c9b2af04d07afa80315/

Signed-off-by: Frank Vanbever <frank.vanbever@essensium.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit d059946df0ed896872dcb83cf49635c374e2c203)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/elixir/elixir.mk

@@ -8,7 +8,7 @@ ELIXIR_VERSION = 1.9.4
 ELIXIR_SITE = $(call github,elixir-lang,elixir,v$(ELIXIR_VERSION))
 ELIXIR_LICENSE = Apache-2.0
 ELIXIR_LICENSE_FILES = LICENSE
-ELIXIR_DEPENDENCIES = host-erlang
+HOST_ELIXIR_DEPENDENCIES = host-erlang
 
 define HOST_ELIXIR_BUILD_CMDS
 	$(HOST_MAKE_ENV) $(HOST_CONFIGURE_OPTS) $(MAKE) -C $(@D) compile