Firs this fixes a cp/rm errors that were logged when building the Windows SDK.
There errors happens because the secondary sdk/tools/patch_windows_sdk.sh
was run twice.
Next the shell script is changed to make any error fatal and actually
break the build, like it should.
In the makefile, merge Ying's fix to correctly pass showcommands.
Change-Id: Iee75e42b0b0bbba3c26858c82c933660dc6d74ae
7a508aed2a