[NFC][ELF] Remove redundant and unused file argument from deleteFallThruJmpInsn (#180540)
This was added in 94317878d826 ("LLD Support for Basic Block Sections")
and was only ever used for getRelocTargetVA. It was always redundant
even back then, as it was always the same as is.file, and so passing it
separately made it confusing and less obvious which file it was
referring to, but 2b5cb1bf628f ("[ELF] getRelocTargetVA: pass Ctx and
Relocation. NFC") removed that one use so it is now completely unused.
Remove it, and if anyone ever finds a need for it, they can just use
is.file like should have been done in the first place.