/backstores/rd_mcp assumes PAGE_SIZE=4k during creation

[nablio3000]

On a ppc64le / RHEL 7.1b host, the size for a targetcli created /backstore/rd_mcp is larger than the user-inputted value.

[root@ibm1 ~]# targetcli
targetcli 3.0.pre4 (rtslib 3.0.pre4)
Copyright (c) 2011-2014 by Datera, Inc.
All rights reserved.

/backstores/rd_mcp> create test size=10G nullio=true
Created rd_mcp ramdisk test with size 10G.
Entering new node /backstores/rd_mcp/test
/backstores/rd_mcp/test> ls    
o- test ...................................................... [160.0G, ramdisk, not in use, nullio]
/backstores/rd_mcp/test> 

Looks like a hardcoded assumption for 4k pages here..

[agrover]

tcm.py

# convert to 4k pages
size = round(float(size)/4096)

can be fixed by replacing the hardcode with getpagesize() from the resource module. BTW the use of floats here made me take note, but it appears to be working correctly.