chore: trivial refactoring

[ydah]

No description provided.

[yui-knk]

A lot of changes looks good. Two points I want to keep are:

1. <<- style for "lib/lrama/output.rb" 786330f because they are embedded C codes then it's easy for me to understand what actually embedded by using <<-
2. Previous codes of bc89c4e because currently I feel it's simple to modify or print something in if block when it's one line, this is just my preference.

[ydah]

Sorry for the delay, I changed it back to <<- for lib/lrama/output.rb. Also, I removed the bc89c4e change.

[yui-knk]

Thank you!