Address ament_lint_cmake regressions

[cottsay]

We don't actively enforce linters in ament_cmake, but it's still nice to be consistent.

Addresses:

$ ament_lint_cmake
ament_cmake_core/cmake/symlink_install/ament_cmake_symlink_install.cmake.in:58: Line ends in whitespace [whitespace/eol]

ament_cmake_export_targets/cmake/ament_export_targets.cmake:25: Line ends in whitespace [whitespace/eol]

ament_cmake_gen_version_h/cmake/ament_generate_version_header.cmake:76: Line ends in whitespace [whitespace/eol]
ament_cmake_gen_version_h/cmake/ament_generate_version_header.cmake:156: Extra spaces between 'if' and its () [whitespace/extra]

ament_cmake_gen_version_h/cmake/generate_version_header.cmake.in:11: Lines should be <= 140 characters long [linelength]

ament_cmake_libraries/cmake/ament_libraries_deduplicate.cmake:33: Lines should be <= 140 characters long [linelength]

ament_cmake_python/test/test_package/CMakeLists.txt:17: Mismatching spaces inside () after command [whitespace/mismatch]


7 errors