perf report: Fix some option handling on --stdio

There's a bug that perf report sometimes ignore some options on --stdio
output. This bug is triggered only if a related config variable is set.
For example, let's assume we have a following config file.

$ cat ~/.perfconfig
[call-graph]
print-type = graph
[hist]
percentage = absolute

Then, following perf config will not honor some options.

$ perf record -ag sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.199 MB perf.data (77 samples) ]

$ perf report -g none --stdio
# To display the perf.data header info, please use --header/--header-only options.
#
# Samples: 77 of event 'cycles'
# Event count (approx.): 25425383
#
# Overhead Command Shared Object Symbol
# ........ ............... ....................... ..............
#
16.34% swapper [kernel.vmlinux] [k] intel_idle
|
---intel_idle
cpuidle_enter_state
cpuidle_enter
cpu_startup_entry
...

With '-g none' option, it should not show callchains, but it still shows
callchains. However it works as expected on --tui output.

Similarly, '--percentage relative' option is not work and still shows a
absolute percentage values.

Looking at the source, I found that those setting were overwritten by
config variables when setup_pager() called. The setup_pager() is to
start a pager process so that it can manage long lines of output on the
stdio mode. But as it calls the perf_config() after parsing arguments,
the settings were overwritten regardless of command line options.

The reason it calls perf_config() is to find the 'pager_program' which
might be set by a config variable, I guess. However current perf code
does not provide the config variable for it, so it's just meaningless
IMHO. Eliminating the call makes the option working as expected.

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

tools/perf/util/cache.h

···
 
 /* pager.c */
 extern void setup_pager(void);
-extern const char *pager_program;
 extern int pager_in_use(void);
 extern int pager_use_color;
 

tools/perf/util/environment.c

···
  */
 #include "cache.h"
 
-const char *pager_program;
 int pager_use_color = 1;

tools/perf/util/pager.c

···
 
 	if (!isatty(1))
 		return;
-	if (!pager) {
-		if (!pager_program)
-			perf_config(perf_default_config, NULL);
-		pager = pager_program;
-	}
 	if (!pager)
 		pager = getenv("PAGER");
 	if (!(pager || access("/usr/bin/pager", X_OK)))