hw: misc: edu: fix 2 off-by-one errors

hw: misc: edu: fix 2 off-by-one errors

In the case that size1 was zero, because of the explicit
'end1 > addr' check, the range check would fail and the error
message would read as shown below. The correct comparison
is 'end1 >= addr'.

EDU: DMA range 0x40000-0x3ffff out of bounds (0x40000-0x40fff)!

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1254
Signed-off-by: Chris Friedt <cfriedt@meta.com>
[thuth: Adjust patch with regards to the "end1 <= end2" check]
Message-ID: <20221018122551.94567-1-cfriedt@meta.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>