signal/testing: Don't look for __SI_FAULT in userspace

Fix the debug print statements in these tests where they reference
si_codes and in particular __SI_FAULT.  __SI_FAULT is a kernel
internal value and should never be seen by userspace.

While I am in there also fix si_code_str.  si_codes are an enumeration
there are not a bitmap so == and not & is the apropriate operation to
test for an si_code.

Cc: Dave Hansen <dave.hansen@linux.intel.com>
Fixes: 5f23f6d082 ("x86/pkeys: Add self-tests")
Fixes: e754aedc26 ("x86/mpx, selftests: Add MPX self test")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

tools/testing/selftests/x86/mpx-mini-test.c

@@ -391,8 +391,7 @@ void handler(int signum, siginfo_t *si, void *vucontext)
 		br_count++;
 		dprintf1("#BR 0x%jx (total seen: %d)\n", status, br_count);
 
-#define __SI_FAULT      (3 << 16)
-#define SEGV_BNDERR     (__SI_FAULT|3)  /* failed address bound checks */
+#define SEGV_BNDERR     3  /* failed address bound checks */
 
 		dprintf2("Saw a #BR! status 0x%jx at %016lx br_reason: %jx\n",
 				status, ip, br_reason);

tools/testing/selftests/x86/protection_keys.c

@@ -212,19 +212,18 @@ void dump_mem(void *dumpme, int len_bytes)
 	}
 }
 
-#define __SI_FAULT      (3 << 16)
-#define SEGV_BNDERR     (__SI_FAULT|3)  /* failed address bound checks */
-#define SEGV_PKUERR     (__SI_FAULT|4)
+#define SEGV_BNDERR     3  /* failed address bound checks */
+#define SEGV_PKUERR     4
 
 static char *si_code_str(int si_code)
 {
-	if (si_code & SEGV_MAPERR)
+	if (si_code == SEGV_MAPERR)
 		return "SEGV_MAPERR";
-	if (si_code & SEGV_ACCERR)
+	if (si_code == SEGV_ACCERR)
 		return "SEGV_ACCERR";
-	if (si_code & SEGV_BNDERR)
+	if (si_code == SEGV_BNDERR)
 		return "SEGV_BNDERR";
-	if (si_code & SEGV_PKUERR)
+	if (si_code == SEGV_PKUERR)
 		return "SEGV_PKUERR";
 	return "UNKNOWN";
 }