erofs: using switch-case while checking the inode type.

while filling the linux inode, using switch-case statement to check
the type of inode.
switch-case statement looks more clean here.

Signed-off-by: Pratik Shinde <pratikshinde320@gmail.com>
Reviewed-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190830095615.10995-1-pratikshinde320@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>