Resolve a bug where the initial ReadEdidData 'for' loop would loop infinitely, since the Index variable was declared as UINT8, and 'EDID_BLOCK_SIZE * 2' is 256. 
Resolve a bug where the initial ReadEdidData 'for' loop would loop
infinitely, since the Index variable was declared as UINT8, and
'EDID_BLOCK_SIZE * 2' is 256. 

In the EFI_SUCCESS return path of CirrusLogic5430VideoModeSetup, check
that 'EdidOverrideDataBlock' has been allocated before attempting to
free this memory.


git-svn-id: 5648d1bec6962b0a6d1d1b40eba8cf5cdb62da3d@6688 6f19259b-4bc3-4df7-8a09-765794883524

MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2