microblaze: Correct ec mask in debug print

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
diff --git a/linux-user/main.c b/linux-user/main.c
index e651bfd..9160087 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -2258,7 +2258,7 @@
                     break;
                 default:
                     printf ("Unhandled hw-exception: 0x%x\n",
-                            env->sregs[SR_ESR] & 5);
+                            env->sregs[SR_ESR] & ESR_EC_MASK);
                     cpu_dump_state(env, stderr, fprintf, 0);
                     exit (1);
                     break;