selftest: wic: respect IMAGE_LINK_NAME also in test_rawcopy_plugin_qemu

* this one is more tricky, because the test_rawcopy_plugin.wks.in file
  is used while building core-image-minimal-mtdutils, but the image filename
  inside wks.in is from core-image-minimal, so we cannot just let bitbake
  expand IMAGE_LINK_NAME, use separate variable set in the same config fragment
  IMAGE_LINK_NAME_CORE_IMAGE_MINIMAL

[YOCTO #12937]

(From OE-Core rev: 8864ee825fdc52fe7a8cf93876c81c639fba66f4)

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta-selftest/wic/test_rawcopy_plugin.wks.in

@@ -1,6 +1,6 @@
 # short-description: This file is used in oe-selftest wic module to test rawcopy plugin
 
 part /boot --active --source bootimg-pcbios
-part / --source rawcopy --sourceparams="file=core-image-minimal-${MACHINE}.ext4" --use-uuid
+part / --source rawcopy --sourceparams="file=${IMAGE_LINK_NAME_CORE_IMAGE_MINIMAL}.ext4" --use-uuid
 
 bootloader  --timeout=0 --append="console=ttyS0,115200n8"

meta/lib/oeqa/selftest/cases/wic.py

@@ -1034,9 +1034,13 @@ class Wic2(WicTestCase):
         config = 'IMAGE_FSTYPES = "ext4"\n'
         self.append_config(config)
         bitbake('core-image-minimal')
+        image_link_name = get_bb_var('IMAGE_LINK_NAME', 'core-image-minimal')
         self.remove_config(config)
 
-        config = 'IMAGE_FSTYPES = "wic"\nWKS_FILE = "test_rawcopy_plugin.wks.in"\n'
+        config = 'IMAGE_FSTYPES = "wic"\n' \
+                 'IMAGE_LINK_NAME_CORE_IMAGE_MINIMAL = "%s"\n'\
+                 'WKS_FILE = "test_rawcopy_plugin.wks.in"\n'\
+                 % image_link_name
         self.append_config(config)
         bitbake('core-image-minimal-mtdutils')
         self.remove_config(config)