mm/debug: fix missing space in case statement

In setup_vm_debug() , the case statement for 'p' option is written as
'case'p':' without a space between 'case' and the character constant.
While this is syntactically valid C, it violates the Linux kernel coding
style, which requires a space after 'case'. This patch adds the missing
space to comply with coding standards.

Link: https://lkml.kernel.org/r/20251103065910.2196-1-zhangchujun@cmss.chinamobile.com
Signed-off-by: Zhang Chujun <zhangchujun@cmss.chinamobile.com>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>