procfs: fix possible double mmput() in do_procmap_query()

In the Linux kernel, the following vulnerability has been resolved:

procfs: fix possible double mmput() in do_procmap_query()

When user provides incorrectly sized buffer for build ID for PROCMAP_QUERY

we return with -ENAMETOOLONG error. After recent changes this condition

happens later, after we unlocked mmap_lock/per-VMA lock and did mmput(),

so original goto out is now wrong and will double-mmput() mm_struct. Fix

by jumping further to clean up only vm_file and name_buf.