[c-index-test] Fix warnings about unused results from chdir().
Patch from Edwin Vane!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@170366 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/c-index-test/c-index-test.c b/tools/c-index-test/c-index-test.c
index 7a36d09..be2b6fc 100644
--- a/tools/c-index-test/c-index-test.c
+++ b/tools/c-index-test/c-index-test.c
@@ -2813,9 +2813,13 @@
         goto cdb_end;
       }
 
-      chdir(buildDir);
-      CCmds = clang_CompilationDatabase_getAllCompileCommands(db);
+      if (chdir(buildDir) != 0) {
+        printf("Could not chdir to %s\n", buildDir);
+        errorCode = -1;
+        goto cdb_end;
+      }
 
+      CCmds = clang_CompilationDatabase_getAllCompileCommands(db);
       if (!CCmds) {
         printf("compilation db is empty\n");
         errorCode = -1;
@@ -2834,7 +2838,11 @@
         CCmd = clang_CompileCommands_getCommand(CCmds, i);
 
         wd = clang_CompileCommand_getDirectory(CCmd);
-        chdir(clang_getCString(wd));
+        if (chdir(clang_getCString(wd)) != 0) {
+          printf("Could not chdir to %s\n", clang_getCString(wd));
+          errorCode = -1;
+          goto cdb_end;
+        }
         clang_disposeString(wd);
 
         numArgs = clang_CompileCommand_getNumArgs(CCmd);