pkg-autotools: fix bad GETTEXTIZE_OPT assignment

HOST_PKG_GETTEXTIZE_OPT should get assigned PKG_GETTEXTIZE_OPT and not
PKG_GETTEXTIZE. Fixes:
http://autobuild.buildroot.net/results/087/087e860173069f58fa9ceb2460d7455d31b2dff8/

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/pkg-autotools.mk

@@ -97,7 +97,7 @@ endif
 
 ifndef $(2)_GETTEXTIZE_OPT
  ifdef $(3)_GETTEXTIZE_OPT
-  $(2)_GETTEXTIZE_OPT = $$($(3)_GETTEXTIZE)
+  $(2)_GETTEXTIZE_OPT = $$($(3)_GETTEXTIZE_OPT)
  else
   $(2)_GETTEXTIZE_OPT ?= -f
  endif