cmds/free: refactored linux-specific functions
cmds/free: refactored linux-specific functions

hugelgupf/u-root,hugelgupf/u-root,rminnich/u-root,hugelgupf/u-root,hugelgupf/u-root,GanShun/u-root,GanShun/u-root,rminnich/u-root,u-root/u-root,GanShun/u-root,u-root/u-root,rminnich/u-root,rminnich/u-root,u-root/u-root