VMware: Remove redundant extend disk API call

VMware: Remove redundant extend disk API call

Extend virtual disk API is called during volume creation from image if
the image size is less than volume size. In the case of streamOptimized
and sparse vmdk images, the size of the virtual disk created from the
image can be greater than image size and equal to the volume size. For
example, streamOptimized image created from a new 1GB volume has size
69120 bytes and the size of the virtual disk created from this image
is 1GB. Therefore, relying on image size to invoke extend API might
result in VIM API fault, if the virtual disk size is same as the target
size (volume size). The fix is to read the current virtual disk size to
decide whether extend disk needs to be invoked or not.

Closes-Bug: #1301854
Change-Id: I990ac0b9aef68b3ef8b6d67188db8d44b5c29599