Rename mkuserimg_mke2fs.sh to mkuserimg_mke2fs

This is in line with the change of mkuserimg_mke2fs.sh to python binary.
And we will remove the old mkuserimg_mke2fs.sh later.

Bug: 112555072
Bug: 63866463
Test: run change_security_patch_ver.sh
Change-Id: I066f5f95039e1833415207c8417ab07b0dca9091