CHROMIUM: Fix import processing.

Fix the code that checks whether variable matches an import
declaration. The current code would incorrectly import *all* variables
for jobs that have at least one import declaration.

BUG=chromium:889724
TEST=Image boots and passes tests.
CQ-DEPEND=CL:1247745

Reviewed-on: https://chromium-review.googlesource.com/1247642
Change-Id: I9f2883edc55aa8b6c4ff68a4fb82b0b1a8aca080
diff --git a/init/job_class.c b/init/job_class.c
index f68e6bf..643be2e 100644
--- a/init/job_class.c
+++ b/init/job_class.c
@@ -490,11 +490,11 @@
 
 		elen = strcspn(*e, "=");
 		for (match = class->import; match && *match; match++) {
-			if ((strncmp (*match, *e, elen) == 0) && !match[elen])
+			if ((strncmp (*match, *e, elen) == 0) && ! (*match)[elen])
 				break;
 		}
 
-		if (! match)
+		if (! match || ! *match)
 			continue;
 
 		if (! environ_add (env, parent, len, TRUE, *e))