perf tools Documentation: Fix diverse typos

Go over the tools/ files that are maintained in Arnaldo's tree and
fix common typos: half of them were in comments, the other half
in JSON files.

No change in functionality intended.

Committer notes:

This was split from a larger patch as there are code that is,
additionally, maintained outside the kernel tree, so to ease cherry
picking and/or backporting, split this into multiple patches.

In this particular case, it affects documentation, so may be interesting
to cherry pick as it is information that is presented to the user.

Signed-off-by: Ingo Molnar <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/Documentation/perf-list.txt

···
 Other PMUs and global measurements are normally root only.
 Some event qualifiers, such as "any", are also root only.
 
-This can be overriden by setting the kernel.perf_event_paranoid
+This can be overridden by setting the kernel.perf_event_paranoid
 sysctl to -1, which allows non root to use these events.
 
 For accessing trace point events perf needs to have read access to

tools/perf/Documentation/perf-report.txt

···
 	          Usually more convenient to use --branch-history for this.
 
 	value can be:
-	- percent: diplay overhead percent (default)
+	- percent: display overhead percent (default)
 	- period: display event period
 	- count: display event count
 

tools/perf/Documentation/perf-stat.txt

···
 	  /sys/bus/event_source/devices/<pmu>/format/*
 
 	Note that the last two syntaxes support prefix and glob matching in
-	the PMU name to simplify creation of events accross multiple instances
+	the PMU name to simplify creation of events across multiple instances
 	of the same type of PMU in large systems (e.g. memory controller PMUs).
 	Multiple PMU instances are typical for uncore PMUs, so the prefix
 	'uncore_' is also ignored when performing this match.
···
 for best results. Otherwise the bottlenecks may be inconsistent
 on workload with changing phases.
 
-This enables --metric-only, unless overriden with --no-metric-only.
+This enables --metric-only, unless overridden with --no-metric-only.
 
 To interpret the results it is usually needed to know on which
 CPUs the workload runs on. If needed the CPUs can be forced using