Documentation: trace/ftrace: drop doubled words

Drop the doubled words "for" and "that".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Link: https://lore.kernel.org/r/20200703212453.30553-2-rdunlap@infradead.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/trace/ftrace.rst

@@ -561,7 +561,7 @@ of ftrace. Here is a list of some of the key files:
 
   trace_marker_raw:
 
-	This is similar to trace_marker above, but is meant for for binary data
+	This is similar to trace_marker above, but is meant for binary data
 	to be written to it, where a tool can be used to parse the data
 	from trace_pipe_raw.
 
@@ -1394,7 +1394,7 @@ an example::
    => x86_64_start_reservations
    => x86_64_start_kernel
 
-Here we see that that we had a latency of 16 microseconds (which is
+Here we see that we had a latency of 16 microseconds (which is
 very good). The _raw_spin_lock_irq in run_timer_softirq disabled
 interrupts. The difference between the 16 and the displayed
 timestamp 25us occurred because the clock was incremented