qemu: driver: Improve error suppression in qemuDomainStorageUpdatePhysical
qemu: driver: Improve error suppression in qemuDomainStorageUpdatePhysical

None of the callers of qemuDomainStorageUpdatePhysical care about
errors.

Use the new flag for qemuDomainStorageOpenStat which suppresses some
errors and move the reset of the rest of the uncommon errors into this
function. Document what is happening in a comment for the function.

Signed-off-by: Peter Krempa <2cf5c04c61aa466e4a47bfedc747d17279c72ffc@redhat.com>
Reviewed-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>

crobinso/libvirt,nertpinx/libvirt,crobinso/libvirt,jardasgit/libvirt,andreabolognani/libvirt,andreabolognani/libvirt,jfehlig/libvirt,olafhering/libvirt,zippy2/libvirt,crobinso/libvirt,jardasgit/libvirt,andreabolognani/libvirt,crobinso/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,libvirt/libvirt,jfehlig/libvirt,olafhering/libvirt,zippy2/libvirt,nertpinx/libvirt,libvirt/libvirt,zippy2/libvirt,libvirt/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,nertpinx/libvirt,nertpinx/libvirt,jardasgit/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,olafhering/libvirt,jardasgit/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,zippy2/libvirt,libvirt/libvirt,jardasgit/libvirt,olafhering/libvirt,andreabolognani/libvirt