fs/binfmt_flat.c: remove set but not used variable 'inode'

fs/binfmt_flat.c: remove set but not used variable 'inode'

Fixes gcc '-Wunused-but-set-variable' warning:

  fs/binfmt_flat.c: In function load_flat_file:
  fs/binfmt_flat.c:419:16: warning: variable inode set but not used [-Wunused-but-set-variable]

It's never used and can be removed.

Link: http://lkml.kernel.org/r/20190525125341.9844-1-yuehaibing@huawei.com
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>