scripts/gdb: fix 'lx-current' for x86

When printing the name of the current process, it will report an error:
(gdb) p $lx_current().comm Python Exception <class 'gdb.error'> No symbol
"current_task" in current context.: Error occurred in Python: No symbol
"current_task" in current context.

Because e57ef2e ("x86: Put hot per CPU variables into a struct")
changed it.

Link: https://lkml.kernel.org/r/20230204090139.1789264-1-xiehuan09@gmail.com
Fixes: e57ef2e ("x86: Put hot per CPU variables into a struct")
Signed-off-by: Jeff Xie <xiehuan09@gmail.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: Jeff Xie

scripts/gdb/linux/cpus.py

@@ -163,7 +163,7 @@ def get_current_task(cpu):
     task_ptr_type = task_type.get_type().pointer()
 
     if utils.is_target_arch("x86"):
-         var_ptr = gdb.parse_and_eval("&current_task")
+         var_ptr = gdb.parse_and_eval("&pcpu_hot.current_task")
          return per_cpu(var_ptr, cpu).dereference()
     elif utils.is_target_arch("aarch64"):
          current_task_addr = gdb.parse_and_eval("$SP_EL0")