[DWP] Fix writeStringsAndOffsets declaration

[HighW4y2H3ll]

The definition of writeStringsAndOffsets is changed since: #167457
Update its declaration in the header accordingly.

[llvm-ci]

LLVM Buildbot has detected a new failure on builder ppc64le-mlir-rhel-clang running on ppc64le-mlir-rhel-test while building llvm at step 3 "clean-build-dir".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/129/builds/35855

Here is the relevant piece of the build log for the reference

Step 3 (clean-build-dir) failure: Delete failed. (failure) (timed out)
Step 4 (cmake-configure) failure: cmake (failure) (timed out)
command timed out: 1200 seconds without output running [b'cmake', b'-DLLVM_TARGETS_TO_BUILD=PowerPC', b'-DLLVM_INSTALL_UTILS=ON', b'-DCMAKE_CXX_STANDARD=17', b'-DLLVM_ENABLE_PROJECTS=mlir', b'-DLLVM_LIT_ARGS=-vj 256', b'-DCMAKE_C_COMPILER_LAUNCHER=ccache', b'-DCMAKE_CXX_COMPILER_LAUNCHER=ccache', b'-DCMAKE_BUILD_TYPE=Release', b'-DLLVM_ENABLE_ASSERTIONS=ON', b'-GNinja', b'../llvm-project/llvm'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=1200.284764