Autocorrect of Style/FormatString changes semantics

[khiav223577]

Expected behavior

Autocorrect should not change the behavior of the code.

Actual behavior

Autocorrect changed the behavior of the code.

Steps to reproduce the problem

Add test.rb:

a = 1
result = sprintf('%04d', a + 3)
p result

Run ruby test.rb, it will print "0004".

Add .rubocop.yml:

Style/FormatString:
  EnforcedStyle: percent
  Enabled: true

Run rubocop --auto-correct test.rb in command line.
The auto-corrected test.rb will be:

a = 1
result = '%04d' % a + 3
p result

It will raise test.rb:2:in '+': no implicit conversion of Integer into String (TypeError) when running it.
Expect the corrected test.rb to be

a = 1
result = '%04d' % (a + 3)
p result

RuboCop version

$ [bundle exec] rubocop -V
1.4.1 (using Parser 2.7.2.0, rubocop-ast 1.1.1, running on ruby 2.5.5 x86_64-linux)