perf docs: Correct typo of event_sources

The sysfs directory is called event_source.

Before:

  $ ls -la /sys/bus/event_sources/devices/cpu/format/
  ls: cannot access '/sys/bus/event_sources/devices/cpu/format/': No such file or directory
  $

After:

  $ ls -la /sys/bus/event_source/devices/cpu/format/
  total 0
  drwxr-xr-x. 2 root root    0 Jun  2 15:36 .
  drwxr-xr-x. 6 root root    0 Jun  2 15:35 ..
  -r--r--r--. 1 root root 4096 Jun  2 15:36 any
  -r--r--r--. 1 root root 4096 Jun  2 15:36 cmask
  -r--r--r--. 1 root root 4096 Jun  2 15:36 edge
  -r--r--r--. 1 root root 4096 Jun  2 15:36 event
  -r--r--r--. 1 root root 4096 Jun  2 15:36 frontend
  -r--r--r--. 1 root root 4096 Jun  2 15:36 inv
  -r--r--r--. 1 root root 4096 Jun  2 15:36 ldlat
  -r--r--r--. 1 root root 4096 Jun  2 15:36 offcore_rsp
  -r--r--r--. 1 root root 4096 Jun  2 15:36 pc
  -r--r--r--. 1 root root 4096 Jun  2 15:36 umask
  $
Reviewed-by: NSandipan Das <sandipan.das@amd.com>
Signed-off-by: NIan Rogers <irogers@google.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
Cc: Alyssa Ross <hi@alyssa.is>
Cc: German Gomez <german.gomez@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Joshua Martinez <joshuamart@google.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Like Xu <likexu@tencent.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zhengjun Xing <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20220603045744.2815559-1-irogers@google.comReported-by: NKevin Nomura <nomurak@google.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-record.txt

@@ -33,7 +33,7 @@ OPTIONS
         - a raw PMU event in the form of rN where N is a hexadecimal value
           that represents the raw register encoding with the layout of the
           event control registers as described by entries in
-          /sys/bus/event_sources/devices/cpu/format/*.
+          /sys/bus/event_source/devices/cpu/format/*.
 
         - a symbolic or raw PMU event followed by an optional colon
 	  and a list of event modifiers, e.g., cpu-cycles:p.  See the

tools/perf/Documentation/perf-stat.txt

@@ -39,7 +39,7 @@ report::
 	- a raw PMU event in the form of rN where N is a hexadecimal value
 	  that represents the raw register encoding with the layout of the
 	  event control registers as described by entries in
-	  /sys/bus/event_sources/devices/cpu/format/*.
+	  /sys/bus/event_source/devices/cpu/format/*.
 
         - a symbolic or raw PMU event followed by an optional colon
 	  and a list of event modifiers, e.g., cpu-cycles:p.  See the

tools/perf/Documentation/perf-top.txt

@@ -41,7 +41,7 @@ Default is to monitor all CPUS.
 	(use 'perf list' to list all events) or a raw PMU event in the form
 	of rN where N is a hexadecimal value that represents the raw register
 	encoding with the layout of the event control registers as described
-	by entries in /sys/bus/event_sources/devices/cpu/format/*.
+	by entries in /sys/bus/event_source/devices/cpu/format/*.
 
 -E <entries>::
 --entries=<entries>::