docs: vm: zswap.rst: replace some characters

The conversion tools used during DocBook/LaTeX/html/Markdown->ReST
conversion and some cut-and-pasted text contain some characters that
aren't easily reachable on standard keyboards and/or could cause
troubles when parsed by the documentation build system.

Replace the occurences of the following characters:

	- U+00a0 (' '): NO-BREAK SPACE
	  as it can cause lines being truncated on PDF output

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/9a93b72f99f8f3328269076ceff50248ac9c5af5.1623826294.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Author: mchehab

Documentation/vm/zswap.rst

@@ -10,7 +10,7 @@ Overview
 Zswap is a lightweight compressed cache for swap pages. It takes pages that are
 in the process of being swapped out and attempts to compress them into a
 dynamically allocated RAM-based memory pool.  zswap basically trades CPU cycles
-for potentially reduced swap I/O.  This trade-off can also result in a
+for potentially reduced swap I/O.  This trade-off can also result in a
 significant performance improvement if reads from the compressed cache are
 faster than reads from a swap device.
 
@@ -26,7 +26,7 @@ faster than reads from a swap device.
   performance impact of swapping.
 * Overcommitted guests that share a common I/O resource can
   dramatically reduce their swap I/O pressure, avoiding heavy handed I/O
-  throttling by the hypervisor. This allows more work to get done with less
+  throttling by the hypervisor. This allows more work to get done with less
   impact to the guest workload and guests sharing the I/O subsystem
 * Users with SSDs as swap devices can extend the life of the device by
   drastically reducing life-shortening writes.