ejabberd: Replace $(HOST_DIR) to /usr in ERL path

Previously, it was working by luck. Buildroot has fixed its definition
of HOST_DIR and pkg-autotools.mk uses the classical /usr prefix. So,
fix this sed expression to correctly replace $(HOST_DIR) by /usr in ERL
path.

Signed-off-by: Johan Oudinet <johan.oudinet@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/ejabberd/ejabberd.mk

@@ -36,9 +36,9 @@ define EJABBERD_INSTALL_TARGET_CMDS
 	$(TARGET_MAKE_ENV) $(MAKE) DESTDIR=$(TARGET_DIR) install -C $(@D)
 endef
 
-# Delete HOST_DIR prefix from ERL path in ejabberctl script.
+# Replace HOST_DIR prefix to /usr in ERL path of ejabberctl script.
 define EJABBERD_FIX_EJABBERDCTL
-	$(SED) 's,ERL=$(HOST_DIR),ERL=,' '$(TARGET_DIR)/usr/sbin/ejabberdctl'
+	$(SED) 's,ERL=$(HOST_DIR),ERL=/usr,' '$(TARGET_DIR)/usr/sbin/ejabberdctl'
 endef
 
 EJABBERD_POST_INSTALL_TARGET_HOOKS += EJABBERD_FIX_EJABBERDCTL