perf tools: Remove (null) value of "Sort order" for perf mem report

When '--sort' is not set, 'perf mem report" will print a null pointer as
the output value of sort order, so fix it.

Example:

Before this patch:

 $ perf mem report
 # To display the perf.data header info, please use --header/--header-only options.
 #
 # Samples: 18  of event 'cpu/mem-loads/pp'
 # Total weight : 188
 # Sort order   : (null)
 #
 ...

After this patch:

 $ perf mem report
 # To display the perf.data header info, please use --header/--header-only options.
 #
 # Samples: 18  of event 'cpu/mem-loads/pp'
 # Total weight : 188
 # Sort order   : local_weight,mem,sym,dso,symbol_daddr,dso_daddr,snoop,tlb,locked
 #
 ...

Signed-off-by: Yunlong Song <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions