More glue fails and sneak case

Hi, I was running linting and found this:

test.R
```
df <- data.frame(list(
a = c(1, 2, 3)
))

v <- "a"

dplyr::mutate(df, !!paste0(tolower(v), "_l") := df$a * 2)
```

The output of the linting:
```
test.r:7:31: style: [object_name_linter] Variable and function name style should be snake_case or symbols.
dplyr::mutate(df, !!paste0(v, "_l") := df$a * 2)
```

Thx!