scripts/gdb: disable pagination while printing from breakpoint handler

While reporting the (refreshed) list of modules on automatic updates we
may hit the page boundary of the output console and cause a stop if
pagination is enabled.  However, gdb does not accept user input while
running over the breakpoint handler.  So we get stuck, and the user is
forced to interrupt gdb.

Resolve this by disabling pagination during automatic symbol updates.  We
restore the user's configuration once done.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>