[clang-tidy] fixed misc-unused-parameters omitting parameters default value

Summary:
Bug: https://bugs.llvm.org/show_bug.cgi?id=34450

**Problem:**

Clang-tidy check misc-unused-parameters omits parameter default value what results in its complete removal. Compilation errors might occur after clang-tidy fix.

**Patch description:**

Changed removal range. The range should end after parameter declarator, not after whole parameter declaration (which might contain a default value).

Reviewers: alexfh, xazax.hun

Reviewed By: alexfh

Subscribers: JDevlieghere, cfe-commits

Tags: #clang-tools-extra

Patch by Pawel Maciocha!

Differential Revision: https://reviews.llvm.org/D37566

llvm-svn: 313150