docs: staging/kprobes.rst: Move references to a separate appendix

Kprobes references are currently listed right after kretprobes example,
and appears to be part of the same section. Move this out to a separate
appendix for clarity.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/2bba61cd60eec87fbcca3e4343b7f95afa1178cd.1595331824.git.naveen.n.rao@linux.vnet.ibm.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/staging/kprobes.rst

@@ -20,6 +20,7 @@ Kernel Probes (Kprobes)
   10. Deprecated Features
   Appendix A: The kprobes debugfs interface
   Appendix B: The kprobes sysctl interface
+  Appendix C: References
 
 Concepts: Kprobes and Return Probes
 =========================================
@@ -710,11 +711,6 @@ Kretprobes Example
 
 See samples/kprobes/kretprobe_example.c
 
-For additional information on Kprobes, refer to the following URLs:
-
-- https://www.ibm.com/developerworks/library/l-kprobes/index.html
-- https://www.kernel.org/doc/ols/2006/ols2006v2-pages-109-124.pdf
-
 Deprecated Features
 ===================
 
@@ -797,3 +793,11 @@ Note that this knob *changes* the optimized state. This means that optimized
 probes (marked [OPTIMIZED]) will be unoptimized ([OPTIMIZED] tag will be
 removed). If the knob is turned on, they will be optimized again.
 
+References
+==========
+
+For additional information on Kprobes, refer to the following URLs:
+
+- https://www.ibm.com/developerworks/library/l-kprobes/index.html
+- https://www.kernel.org/doc/ols/2006/ols2006v2-pages-109-124.pdf
+