docs: networking: device_drivers: fix bad usage of UTF-8 chars

Probably because the original file was pre-processed by some
tool, both i40e.rst and iavf.rst files are using this character:

	- U+2013 ('–'): EN DASH

meaning an hyphen when calling a command line application, which
is obviously wrong. So, replace them by an hyphen, ensuring
that it will be properly displayed as literals when building
the documentation.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/95eb2a48d0ca3528780ce0dfce64359977fa8cb3.1620744606.git.mchehab+huawei@kernel.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/networking/device_drivers/ethernet/intel/i40e.rst

@@ -173,7 +173,7 @@ Director rule is added from ethtool (Sideband filter), ATR is turned off by the
 driver. To re-enable ATR, the sideband can be disabled with the ethtool -K
 option. For example::
 
-  ethtool –K [adapter] ntuple [off|on]
+  ethtool -K [adapter] ntuple [off|on]
 
 If sideband is re-enabled after ATR is re-enabled, ATR remains enabled until a
 TCP-IP flow is added. When all TCP-IP sideband rules are deleted, ATR is
@@ -688,7 +688,7 @@ shaper bw_rlimit: for each tc, sets minimum and maximum bandwidth rates.
 Totals must be equal or less than port speed.
 
 For example: min_rate 1Gbit 3Gbit: Verify bandwidth limit using network
-monitoring tools such as ifstat or sar –n DEV [interval] [number of samples]
+monitoring tools such as `ifstat` or `sar -n DEV [interval] [number of samples]`
 
 2. Enable HW TC offload on interface::
 

Documentation/networking/device_drivers/ethernet/intel/iavf.rst

@@ -179,7 +179,7 @@ shaper bw_rlimit: for each tc, sets minimum and maximum bandwidth rates.
 Totals must be equal or less than port speed.
 
 For example: min_rate 1Gbit 3Gbit: Verify bandwidth limit using network
-monitoring tools such as ifstat or sar –n DEV [interval] [number of samples]
+monitoring tools such as ``ifstat`` or ``sar -n DEV [interval] [number of samples]``
 
 NOTE:
   Setting up channels via ethtool (ethtool -L) is not supported when the