Technically he's right, as the report refers to him as Corney.
If you look at it, it looks like Comey, but the R and the N are close together only making it look like an M.
Try opening the report and searching for Comey - you wont find any.
Search for Corney, and there will be 163 matches found.
Inspector General's Report of the Review of Four FISA Applications
https://www.justice.gov/storage/120919-examination.pdf
From Spring onward, James Comey and Devin Nunes have made various references in their tweets regarding corn, corn fields, and harvest. Who knows what that all means...