scripts/gdb: Fix gdb 'lx-symbols' command

Currently the command 'lx-symbols' in gdb exits with the error`Function
"do_init_module" not defined in "kernel/module.c"`. This occurs because
the file kernel/module.c was moved to kernel/module/main.c.

Fix this breakage by changing the path to "kernel/module/main.c" in
LoadModuleBreakpoint.

Signed-off-by: Khalid Masum <khalid.masum.92@gmail.com>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Fixes: cfc1d277

 ("module: Move all into module/")
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>