Update git submodules

* Update docs/submodules/storperf from branch 'master'
  - Corrects url in docs/index.rst

    The toctree in docs/index.rst point to ./user/installation.rst instead of
    ./testing/user/installation.rst
    JIRA: STORPERF-208

    Change-Id: If58eef5bc4eddb8fba2030c5e80aac1f45e85288
    Signed-off-by: Shrenik <shrenik.jain@research.iiit.ac.in>

diff --git a/docs/submodules/storperf b/docs/submodules/storperf
index 6ccd0b7..240ad9c 160000 (submodule)
--- a/docs/submodules/storperf
+++ b/docs/submodules/storperf
@@ -1 +1 @@
-Subproject commit 6ccd0b7fc70157707884f44d9657e8eba8145ea4
+Subproject commit 240ad9c3df56d5a5caa741f0a046526ddecd9254