runqemu: check qbconfload before running bitbake

If qbconfload (.qemuboot.conf is found) is present, we can get
DEPLOY_DIR_IMAGE from it rather than "bitbake -e".

(From OE-Core rev: 89e97033a8a27a695567c321ed0ebf17f23f8d9b)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/runqemu

@@ -466,7 +466,7 @@ class BaseConfig(object):
 
             self.check_arg_machine(unknown_arg)
 
-        if not self.get('DEPLOY_DIR_IMAGE'):
+        if not (self.get('DEPLOY_DIR_IMAGE') or self.qbconfload):
             self.load_bitbake_env()
             s = re.search('^DEPLOY_DIR_IMAGE="(.*)"', self.bitbake_e, re.M)
             if s: