cmd/compile/internal/liveness: remove repetitive word

Change-Id: I27789840d92cc2c1e799db5b58e1eb1570e264df
Reviewed-on: https://go-review.googlesource.com/c/go/+/523235
TryBot-Result: Gopher Robot <[email protected]>
Reviewed-by: Matthew Dempsky <[email protected]>
Run-TryBot: Matthew Dempsky <[email protected]>
Auto-Submit: Matthew Dempsky <[email protected]>
Reviewed-by: Joedian Reid <[email protected]>
Run-TryBot: shuang cui <[email protected]>

Author: cuishuang

src/cmd/compile/internal/liveness/plive.go

@@ -1080,7 +1080,7 @@ func clobberWalk(b *ssa.Block, v *ir.Name, offset int64, t *types.Type) {
 	}
 }
 
-// clobberPtr generates a clobber of the pointer at offset offset in v.
+// clobberPtr generates a clobber of the pointer at offset in v.
 // The clobber instruction is added at the end of b.
 func clobberPtr(b *ssa.Block, v *ir.Name, offset int64) {
 	b.NewValue0IA(src.NoXPos, ssa.OpClobber, types.TypeVoid, offset, v)