Improve the description of error codes for clSetKernelArg (KhronosGroup#1319)

This would likely have prevented me from creating KhronosGroup#1317 after
reading the spec a bit too quickly.

Fixes KhronosGroup#1317


Change-Id: I1ed3737335edc07747e872821210e5785ae6635a

Signed-off-by: Kevin Petit <kevin.petit@arm.com>

Author: kpet

api/opencl_runtime_layer.asciidoc

@@ -10920,22 +10920,25 @@ endif::cl_khr_depth_images,cl_khr_gl_msaa_sharing[]
   * {CL_INVALID_DEVICE_QUEUE} for an argument declared to be of type _queue_t_
     when the specified _arg_value_ is not a valid device queue object.
     This error code is <<unified-spec, missing before>> version 2.0.
-  * {CL_INVALID_ARG_SIZE} if _arg_size_ does not match the size of the data
-    type for an argument that is not a memory object or if the argument is a
-    memory object and _arg_size_ != `sizeof({cl_mem_TYPE})` or if _arg_size_ is
-    zero and the argument is declared with the local qualifier or if the
-    argument is a sampler and _arg_size_ != `sizeof({cl_sampler_TYPE})`.
+  * {CL_INVALID_ARG_SIZE}
+  ** if _arg_size_ does not match the size of the data type for an argument
+     that is not a memory object, or
+  ** if the argument is a memory object and _arg_size_ != `sizeof({cl_mem_TYPE})`, or
+  ** if _arg_size_ is zero and the argument is declared with the `local` qualifier, or
+  ** if the argument is a sampler and _arg_size_ != `sizeof({cl_sampler_TYPE})`.
   * {CL_MAX_SIZE_RESTRICTION_EXCEEDED} if the size in bytes of the memory
     object (if the argument is a memory object) or _arg_size_ (if the
     argument is declared with `local` qualifier) exceeds a language-
     specified maximum size restriction for this argument, such as the
     *MaxByteOffset* SPIR-V decoration.
     This error code is <<unified-spec, missing before>> version 2.2.
-  * {CL_INVALID_ARG_VALUE} if the argument is an image declared with the
-    `read_only` qualifier and _arg_value_ refers to an image object created
-    with _cl_mem_flags_ of {CL_MEM_WRITE_ONLY} or if the image argument is
-    declared with the `write_only` qualifier and _arg_value_ refers to an
-    image object created with _cl_mem_flags_ of {CL_MEM_READ_ONLY}.
+  * {CL_INVALID_ARG_VALUE}
+  ** if the argument is an image declared with the `read_only` qualifier and
+     _arg_value_ refers to an image object created with _cl_mem_flags_ of
+     {CL_MEM_WRITE_ONLY}, or
+  ** if the image argument is declared with the `write_only` qualifier and
+     _arg_value_ refers to an image object created with _cl_mem_flags_ of
+     {CL_MEM_READ_ONLY}.
   * {CL_OUT_OF_RESOURCES} if there is a failure to allocate resources required
     by the OpenCL implementation on the device.
   * {CL_OUT_OF_HOST_MEMORY} if there is a failure to allocate resources