Update api/cl_khr_command_buffer.asciidoc

Co-authored-by: Ben Ashbaugh <ben.ashbaugh@intel.com>

Author: EwanC

api/cl_khr_command_buffer.asciidoc

@@ -109,7 +109,7 @@ command-queue. The command-buffer itself has no inherent in-order/out-of-order
 property, this ordering is inferred from the command-queue used on command
 recording. {clEnqueueCommandBufferKHR} submissions to an out-of-order queue
 have the same execution semantics are other operations enqueued to an
-out-of-order queue, such as {clEnqueueFillBuffer}. Where execution between
+out-of-order queue, such as {clEnqueueFillBuffer}, where execution between
 enqueued operations may happen concurrently unless dependencies between the
 operations are expressed with events.