config_tools/schema: fix division operator in error messages
The division operator in XPATH is `div`, not `/`. Fix it in an error
message of the assertions.
<xs:assert test="sum(//memory/range[not(@id)]/@size) &gt; (sum(/acrn-config//vm[load_order != 'SERVICE_VM']//memory/size) + sum(/acrn-config//vm[load_order != 'SERVICE_VM']//size_hpa)) * 1024 * 1024">
<xs:annotation acrn:severity="warning" acrn:report-on="/acrn-config//vm[load_order != 'SERVICE_VM']//memory">
- <xs:documentation>The total memory size allocated to all VMs is larger then available host memory ({(sum(/acrn-config//vm[load_order != 'SERVICE_VM']//memory/size) + sum(/acrn-config//vm[load_order != 'SERVICE_VM']//size_hpa))} MB > {sum(//memory/range[not(@id)]/@size) / 1048576} MB). Reduce total allocated User VM memory size.</xs:documentation>
+ <xs:documentation>The total memory size allocated to all VMs is larger then available host memory ({(sum(/acrn-config//vm[load_order != 'SERVICE_VM']//memory/size) + sum(/acrn-config//vm[load_order != 'SERVICE_VM']//size_hpa))} MB > {sum(//memory/range[not(@id)]/@size) div 1048576} MB). Reduce total allocated User VM memory size.</xs:documentation>
</xs:annotation>
</xs:assert>
