Fix __pthread_clone on ARM to set errno on failure.

MIPS and x86 appear to have been correct already.

(Also fix unit tests that ASSERT_EQ with errno so that the
arguments are in the retarded junit order.)

Bug: 3461078
Change-Id: I2418ea98927b56e15b4ba9cfec97f5e7094c6291
diff --git a/tests/stubs_test.cpp b/tests/stubs_test.cpp
index 9daaa22..2e1acc1 100644
--- a/tests/stubs_test.cpp
+++ b/tests/stubs_test.cpp
@@ -38,7 +38,7 @@
   errno = 0;
   passwd* pwd = getpwuid(uid);
   ASSERT_TRUE(pwd != NULL);
-  ASSERT_EQ(errno, 0);
+  ASSERT_EQ(0, errno);
   EXPECT_STREQ(username, pwd->pw_name);
   EXPECT_EQ(uid, pwd->pw_uid);
   EXPECT_EQ(uid, pwd->pw_gid);