qa/suites/rados/verify: remove random-distro$

the distro specified by random-distro$ will be overwrited by the one
specfied by valgrind.yaml. and teuthology-suite will give

KeyError: '16.04 not a centos version or codename'

when scheduling a suite involving the facets above. also, i think it's
of not much value to run valgrind/lockdep with different distros.

Signed-off-by: Kefu Chai <kchai@redhat.com>

diff --git a/qa/suites/rados/verify/supported-random-distro$ b/qa/suites/rados/verify/supported-random-distro$
deleted file mode 120000 (symlink)
index 7cef21e..0000000
--- a/qa/suites/rados/verify/supported-random-distro$
+++ /dev/null
@@ -1 +0,0 @@
-../basic/supported-random-distro$
\ No newline at end of file