rdma: correct some spelling mistakes

Change-Id: Ie99ad6db42d3a52bcc7748448c6d5e97e5bad69e
BUG: 1088848
Reported-by: Patrick Matthäi <pmatthaei@debian.org>
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: http://review.gluster.org/7499
Reviewed-by: Vikhyat Umrao <vumrao@redhat.com>
Reviewed-by: Humble Devassy Chirammal <humble.devassy@gmail.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>