top: ignore the SIGHUP signal if running in batch mode

It would appear that openSUSE was the first to release
procps-ng version 4.0.0 (in the tumbleweed distro). As
a result I checked their source rpm and found a couple
of patches I'm porting to newlib for the next release.

This particulate commit was a refactor of the openSUSE
patch 'procps-ng-3.3.8-bnc634840.patch'. Unfortunately
their original patch did not have the intended effect.

That was because the amended signal handling logic was
performed well before the command line parameters were
parsed. So the global 'Batch' flag was in its 0 state.

. what follows is the original openSUSE commit message
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Do not setup SIGHUP signal handler if we are in the batch mode

Top enables a signal handler for the SIGHUP signal (loss of terminal).  While
this makes sense for top's default interactive mode, it doesn't make any sense
for batch mode. If you run top in nohup just to collect data over time and
disconnect top finishes which is not what one would expect.
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Signed-off-by: Jim Warner <james.warner@comcast.net>

top/top.h

@@ -711,6 +711,7 @@ typedef struct WIN_t {
 //atic int           configs_path (const char *const fmts, ...);
 //atic void          configs_reads (void);
 //atic void          parse_args (int argc, char **argv);
+//atic void          signals_set (void);
 //atic void          whack_terminal (void);
 /*------  Windows/Field Groups support  ----------------------------------*/
 //atic void          win_names (WIN_t *q, const char *name);