sparc: disable qtest in make check

We've seen this repeatedly in buildbot but I can now reliably
reproduce it myself too.  With a few hundred runs of 'make check',
qemu-system-sparc will hang consuming 100% CPU.  I've attached GDB
to the hung process and unfortunately, I can't get anything useful
out of GDB (RIP is not a valid simple and there is nothing else on
the stack).

At any rate, since this only manifests in qemu-system-sparc and it
doesn't appear to be a qtest specific problem, I think we should
disable it until the problem is resolved.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/tests/Makefile b/tests/Makefile
index abe9c2a..83145f5 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -65,8 +65,8 @@
 check-qtest-x86_64-y = $(check-qtest-i386-y)
 gcov-files-i386-y += i386-softmmu/hw/mc146818rtc.c
 gcov-files-x86_64-y = $(subst i386-softmmu/,x86_64-softmmu/,$(gcov-files-i386-y))
-check-qtest-sparc-y = tests/m48t59-test$(EXESUF)
-check-qtest-sparc64-y = tests/m48t59-test$(EXESUF)
+#check-qtest-sparc-y = tests/m48t59-test$(EXESUF)
+#check-qtest-sparc64-y = tests/m48t59-test$(EXESUF)
 gcov-files-sparc-y += hw/m48t59.c
 gcov-files-sparc64-y += hw/m48t59.c
 check-qtest-arm-y = tests/tmp105-test$(EXESUF)