perf/test: Speed up test case perf annotate basic tests

perf test 70 takes a long time. One culprit is the output of command
perf annotate. Per default enabled are
- demangle symbol names
- interleave source code with assembly code.
Disable demangle of symbols and abort the annotation
after the first 250 lines.

This speeds up the test case considerable, for example
on s390:

Output before:
# time perf test 70
70: perf annotate basic tests : Ok
.....
real 2m7.467s
user 1m26.869s
sys 0m34.086s
#

Output after:
# time perf test 70
70: perf annotate basic tests : Ok

real 0m3.341s
user 0m1.606s
sys 0m0.362s
#

Signed-off-by: Thomas Richter <[e-mail]>
Reviewed-by: James Clark <[e-mail]>
Cc: Heiko Carstens <[e-mail]>
Cc: Vasily Gorbik <[e-mail]>
Cc: Alexander Gordeev <[e-mail]>
Cc: [e-mail]
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Namhyung Kim <[e-mail]>

tools/perf/tests/shell/annotate.sh

···
   fi
 
   # Generate the annotated output file
-  perf annotate -i "${perfdata}" --stdio 2> /dev/null > "${perfout}"
+  perf annotate --no-demangle -i "${perfdata}" --stdio 2> /dev/null | head -250 > "${perfout}"
 
   # check if it has the target symbol
   if ! grep "${testsym}" "${perfout}"
···
   fi
 
   # check again with a target symbol name
-  if ! perf annotate -i "${perfdata}" "${testsym}" 2> /dev/null | \
-	  grep -m 3 "${disasm_regex}"
+  if ! perf annotate --no-demangle -i "${perfdata}" "${testsym}" 2> /dev/null | \
+	  head -250 | grep -m 3 "${disasm_regex}"
   then
     echo "Basic annotate [Failed: missing disasm output when specifying the target symbol]"
     err=1
···
   fi
 
   # check one more with external objdump tool (forced by --objdump option)
-  if ! perf annotate -i "${perfdata}" --objdump=objdump 2> /dev/null | \
-	  grep -m 3 "${disasm_regex}"
+  if ! perf annotate --no-demangle -i "${perfdata}" --objdump=objdump 2> /dev/null | \
+	  head -250 | grep -m 3 "${disasm_regex}"
   then
     echo "Basic annotate [Failed: missing disasm output from non default disassembler (using --objdump)]"
     err=1