RDMA engine: Change wording of HOWTO section

Change "iWarp" into "iWARP" ("iWarp" is the name of a supercomputer) and
"engines" into "protocols".

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Ren Yufei <renyufei83@yahoo.com.cn>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/HOWTO b/HOWTO
index 3b60f58..72a29a9 100644
--- a/HOWTO
+++ b/HOWTO
@@ -570,9 +570,9 @@
 				for more info on GUASI.
 
 			rdma    The RDMA I/O engine  supports  both  RDMA
-				memory semantic(RDMA_WRITE/RDMA_READ) and
-				channel semantic(Send/Recv) in InfiniBand, RoCE
-				and iWarp environment.
+				memory semantics (RDMA_WRITE/RDMA_READ) and
+				channel semantics (Send/Recv) for the
+				InfiniBand, RoCE and iWARP protocols.
 
 			external Prefix to specify loading an external
 				IO engine object file. Append the engine